Module 02: Atoms and Elements Flashcards
02.01 Atomic Theory 02.02 Electromagnetic Radiation 02.03 Quantization of Energy 02.04 Quantum Models 02.05 Honors Electrons 02.06 Periodic Table 02.07 Periodic Trends 02.08 Contributions to Chemistry
What did John Dalton contribute to science in 1803?
Devised a way to indirectly observe atomic nature
- temperature
- atmospheric conditions
- wind patterns
What does the word “atom” mean?
Derived from the Greek term meaning “cannot be cut into smaller pieces”.
What is Dalton’s Atomic Theory?
All matter is composed of extremely small particles → atoms
- Atoms of element: identical (size, mass, etc)
- not broken down into smaller pieces
Law of Conservation of Mass
Atoms cannot be subdivided, created, or destroyed
Law of Multiple Proportions
Atoms of different elements can combine > compound (whole-number ratio)
What is the Law of Conservation of Mass?
Atoms cannot be subdivided, created, or destroyed
What is the Law of Multiple Proportions?
Atoms of different elements can combine > compound (whole-number ratio)
How did Dalton’s Theory prove durable?
Dalton’s original theory provides explanation to atomic structure. 200 years additional support for theory
Define subatomic particles?
particles smaller than an atom
- Protons
- Neutrons
- Electrons
Explain how J. J. Thomson discovered electrons (1867-1906)?
Experiment:
- loved cathode rays
- discovered smaller, negative particles in an atom
- called: electrons
Conclusion:
Thomson hypothesized that these corpuscles were scattered within a positively charged atom
Explain Ernest Rutherford’s contribution to the understanding of atoms (especially the nucleus)?
Who: Ernest Rutherford (student J. J. Thomson)
Experiment:
behavior particles as they were radiated onto a piece of gold foil
- some particles not pass strait through
- some scattered
- others bounced back
Conclusion:
Something big, positively charged in the center of the atom → nucleus
composed of protons and neutrons
What contribution did James Chadwick make to the understanding of the nucleus?
Experiment:
- Found neutrons
- bombarded beryllium atoms with alpha particles → unknown radiation produced
- Neutral electrical charge
Conclusion:
determined neutron existed in an atom’s nucleus
mass close to the proton
What conclusion did Crookes create related to cathode tubed?
How did Thomson challenge this idea?
Crookes’s Cathode:
Created cathode tube → allowed electrically charged particles flow between electrodes
Conclusion: something was traveling from the negative to the positive side
Thomson’s Electrons:
J. J. Thomas: used cathode ray tubes
negative attracted to the positive side & repelled by the negative side
calculate a mass-to-charge ration
How did Rutherford’s discovery of the nucleus challenge Thomson’s hypothesis regarding electrons?
Assumed fast-moving alpha particles pass through piece of tin foil
if Thomas’s model was right nothing would scatter the rays
scattered particles indicated a nucleus
Explain what the Bohr’s Quantum Model is:
Hypothesis:
The energy of a atoms not continue → only certain values
Proposal:
- emitting energy: higher to lower energy level
- absorbing energy: lower to higher energy level
Electrons:
- fixed energy
- only move
Energy Shell:
layers around the nucleus
- 2 first
- 8 second
Comparative to Solar System:
given away to the electron cloud model:
- orbitals
- brightness correlated to density
How did Schrodinger and Heisenberg’s Electron Cloud Theory replace Bohr’s Quantum Model?
electrons not move in exact orbitals (like solar system)
Existed in the electron cloud
- region around the nucleus - mostly empty space - electrons orbit
Define Atoms:
smallest unit of an element that retains the properties of that element
How does the nucleus compare to the electron cloud?
NUCLEUS:
center
most of the mass
Protons:
- positively charged
Neutrons:
- neutral
- identifies the element
ELECTRON CLOUD
area around the nucleus
majority of the volume
Electrons:
- negative particles
- revolve around the nucleus
- ability move from one electron to another
Define Ions:
atom/molecule with a positive or negative charge
Define Isotopes:
atoms of the same element with different masses due to varying number of neutrons
What is the overall charge of a atom?
Neutral
Rutherford’s famous gold foil experiments shot heavy particles at a thin sheet of gold foil. What did he observe, and why did these observations eventually result in the addition of a nucleus to the atomic model? (3 points)
- Some of the heavy particles bounced off the foil, because there are positive particles spread throughout the atom.
- Some of the heavy particles bounced off the foil, because there is a dense, positive area in the atom.
- The heavy particles all passed straight through the foil, because the atoms are mostly empty space.
- The heavy particles all bounced off the foil, because the subatomic particles have mass and volume.
2.
Some of the heavy particles bounced off the foil, because there is a dense, positive area in the atom.
Modern atomic theory states that atoms are neutral. How is this neutrality achieved? (3 points)
- Equal number of neutrons and protons
- Equal number of protons and electrons
- More electrons than protons
- More neutrons than electrons
2. Equal number of protons and electrons
What is true of neutrons? (3 points)
- They have no charge and are located inside the nucleus.
- They have no charge and are located outside the nucleus.
- They are negatively charged and are located inside the nucleus.
- They are negatively charged and are located outside the nucleus.
- They have no charge and are located inside the nucleus.
In the 1800s, one of the statements in John Dalton’s atomic theory was that atoms are indivisible. Later experimental evidence led to the discovery of subatomic particles such as neutrons, electrons, and protons. What happened to the indivisible atom part of Dalton’s atomic theory, and why? (3 points)
- The entire theory was discarded because Dalton’s scientific reputation was ruined once new evidence invalidated part of his theory.
- The indivisible atom part of the theory was discarded because the consensus of data must exist for theories to be valid.
- The theory remained unchanged because Dalton was correct regarding all other statements within the accepted scientific theory.
- The theory remained unchanged because new data is discarded if it doesn’t fit within the accepted theory.
2. The indivisible atom part of the theory was discarded because the consensus of data must exist for theories to be valid.
Which hypothesis of Thomson’s atomic model was later found to be not true by Niels Bohr and why? (5 points)
J. J. Thomson discovered the electron. However, he concluded that the electrons were scattered within the positively charged atom. A few years later, Niels Bohr disproved Thomson’s hypothesis that elections were randomly scattered in the atom. Comparatively, he posed that electrons moved in orbits around the nucleus. Bohr’s hypothesis was built on Rutherford’s discovery of the atom. Rutherford disproved Thomson’s idea that there was an even distribution of particles in the atom; instead, there is a nucleus in the middle (which he found with hid tin foil experiment).
Hence, if there is a positively charged cluster of particles in the middle, there cannot be electron scattered the way Thomson proposed. So Bohr deduced from Rutherford’s theory of the nucleus that the atom had a “solar system” like structure (which was disproven by Schrodinger and Heisenberg later). The electrons, according to the Bohr, were ordered in layers - orbitals - around the nucleus.
How does energy travel in waves?
The disturbance of the particles of a substance resulting in undulating motion
What discovery did Max Planck make in relation to energy?
“Energy has both wavelike and particle-like properties”
No continuous energy but transfer in packets
Define Quanta:
quantity of energy proportional in magnitude to the frequency of the radiation it represents
What did Albert Einstein say about Plank’s theory regarding energy?
Agreed with Planck
Energy transferred discrete packets called quanta
Define Radiation:
Emission of energy in the form of waves
- repetitive
- come various sizes
- carry energy
Define Electromagnetic Wave:
Wave of energy generated by periodic fluctuation of an electromagnetic field
Describe the structure of an electromagnetic wave?
Trough: lowest point
Crest: highest point
Amplitude: vertical distance between the crest/trough
measures height, intensity
What is the speed of light?
3.0 * 108 m/s
Define wavelength:
Distance between corresponding points on adjacent waves
Consistent between the entire wave
Define Frequency:
waves passing by a fixed amount of time (per second)
Hertz (Hz)
What is the relation between wavelength and frequency?
inverse related
wave period → amount of time it takes for one wavelength to pass through a point ( seconds (s): Hz = 1/2)
Define Wave Period:
amount of time it takes for one wavelength to pass through a point ( seconds (s): Hz = 1/2)
Define Electromagnetic Radiation (EMR)?
Form of energy moves in a wavelike motion as it travels
fluctuating electric and magnetic energy field → oscillate at right angles to each other
Ex:
- visible light
- radio waves
- X-rays
- ultraviolet (UV) light
- gamma rays
What is Radio Waves?
Used for radio, TV antennas, cell phones
What are Micro-Waves?
Used in radar and to heat food (microwave)
What are Infrared radiation?
HEAT → emitted by all objects (use special cameras to detect)
What is Visible radiation?
All the radiation humans can see (light, sun, fire)
What is Ultraviolet light?
Radiated by the sun (uses burns)
Define X-rays:
Used in medical fields to look at bones on the inside
Define Gamma Rays:
Radiation given off by radioactive substances
Electrons have been shown to have both wavelike and particle-like properties. (4 points)
- True
- False
True
Which type of electromagnetic radiation has a lower frequency than infrared radiation? (4 points)
- Gamma rays
- Microwaves
- Visible light
- X‒rays
2. Microwaves
Compared to infrared radiation, an electromagnetic wave that has a lower frequency will also have a ________. (4 points)
- longer wavelength and lower speed
- longer wavelength and equal speed
- shorter wavelength and lower speed
- shorter wavelength and equal speed
2. longer wavelength and equal speed
What is the frequency of a wave with a wavelength of 6.40 x 104 meters? (4 points)
- 1.87 x 10−6 Hz
- 2.13 x 10−4 Hz
- 4.69 x 103 Hz
- 1.92 x 1013 Hz
3. 4.69 x 103 Hz
Formula to determine wavelength:
Wavelength = Speed of Light / Frequency
What happens to electrons of elements when heat/energy is added?
- absorb energy
- transition into a higher energy level
How do electrons move between the excited and ground state?
Excited: particles has higher energy than lowest possible state
Ground: lowest energy state of atom
What is an emission spectrum?
The transition between Excited <> Ground
- emits light (different colors)
- Emission spectrum: spectrum of electromagnetic radiation emitted by source
How do heat, electricity, and light relate to an increase/decrease in energy?
Heat and Electricity → increases energy
Light → decrease in energy
Define a “photon?”
Basic particle representing a quantum of energy
What is a photon of light?
Emitted by an atom when electron transitions into lower energy level
Define a photon of energy?
Amitted by an atom when electron transitions into lower energy level
What is the formula for a energy of a photon?
E = hf
Directly proportional to the frequency of photon’s emission or absorption
- Joules
- h: Planck’s constant → 6.626 * 10-34 (J *s)
- f: frequency of light
- Amount of energy → dependent on frequency of energy source
Define a “scientific model:”
Visual representation of a scientific idea or process and make it easier to learn a new concept
What are the different types of scientific models? (6)
Diagrams, Sketches, or drawings:
- Illustrations of processes
- Labels and icons
2D or 3D:
- Replicas of objects or processes
- ex: Model of a molecule
Simulations:
- Imitates a process to make it as realistic as possible
Infographics:
Explanatory pictures that improve understanding
Maps:
- Model landmarks, land elevations, weather, and more
- direction
- scale calculate distance
- legend to describe symbols and colors
Graphs
- Shows relationships
What is the estimated effective nuclear charge (zeff) felt by the outer shell electrons in calcium (Ca)?
The outer shell electrons feel an estimated effective nuclear charge of about +2. This is because the total nuclear charge (+20) is shielded by the 18 core electrons in the energy levels closer to the nucleus. The equation +20 − 18 = +2 gives the estimated effective nuclear charge felt by each of sulfur’s outer shell electrons.
Oxygen has a negative electron affinity. Does it absorb or release energy when it gains an electron?
When energy is released, the electron affinity value is represented as a negative value.
A scientist needs to determine the reactivity of two elements. One element is a metal, and the other element is a nonmetal. What periodic trend determines the reactivity of both elements?
For metals, as you go down a column, the chemical reactivity increases. As you go right across a row, the chemical reactivity decreases.
For nonmetals, as you go down a column, the chemical reactivity decreases. As you go right across a row, the chemical reactivity increases.
Do elements with a low effective nuclear charge also have low electronegativity? Explain your answer.
Outer shell electrons of elements with low effective nuclear charge usually have low electronegativity values because their nuclei exert a weak attractive force on electrons. However, this isn’t always true. There are exceptions on the periodic table.
Define Quantum Model:
Mathematical model based on quantum theory that represents the probable state of electrons within an atom
What was Niel Bohr’s proposal regarding electrons?
Niels Bohr Proposal: partials that circle the nucleus in shells
- lowest: n = 1
- Next: n = 2
- Number of electrons is equal to neutrons
What is Heisenberg Uncertainty Principle?
Cannot know both the position and the velocity of particle at the same time
What is the Principal Quantum Number?
Any whole number from 1-7
Energy levels around the nucleus
energy shells
- n =1 → inner most, least energetic
- energy increase and n increases
What is the Angular Momentum Quantum Number (I)?
4 types of numbers
- S orbital → round
- P Orbital → shaped like a bumble
- D orbital
- F orbital
Define subshells:
group of orbitals with the same potential energy
Describe the ”s” orbitals from the Angular Momentum Quantum Number:
[1] S → one orbital
- spherical shape
- Electrons arrows
- up: clockwise spin
- down: counterclockwise
Describe the “P” orbitals from the Angular Momentum Quantum Number:
[2] P → three orbitals
- dumbbell-shaped
- Max: 6 electrons
Describe the “d” orbitals from the Angular Momentum Quantum Number:
[3] d → five orbitals
- nondescript shape
- max: 10 electrons
Describe the “f” orbitals from the Angular Momentum Quantum Number:
[4] f → seven orbitals
- nondescript in shape
- Max: 14 electrons
Define electron configuration:
: Arrangement of electrons in energy levels (shells) around nucleus
Define the different parts of electron configuration: 1s22s22p6
- Number of electrons
- Oribtals
- Energy Shells
- Number of electrons: 1s22s22p6
- subshell has limit to the number of electron the orbit can hold
- Adding together = number of electron for element
- Orbitals: 1s22s22p6
- Energy Shells: 1s22s22p6
Define each subshell’s corresponding amount of orbitals and electrons: (s, p, d, f)
See attachment:
What are the [4] levels of configuration?
- Electrons
- Example
- type of subshell
Level 01:
- 2 electrons in s subshell
- Configuration: 1s2
Level 02:
- 8 electrons in p subshell
- Configuration: 1s22s22p6
Level 03:
- 18 electrons
- 2 electrons in s subshell
- 6 in p subshell
- 10 in d subshell
- 4s subshell is filled before 3d
- Configuration: 1s22s22p63s23p64s23d10
Level 04:
- 8 electrons
- 2 in 4s
- 6 in 4p
- Configuration: 1s22s22p63s23p64s23d104p6
Define Ground-State Electron Configuration:
Arrangement that places electrons closest to nucleus
What is the Aufbau Principle?
Quantum model of atom mathematically maps out an atom’s orbitals beyond ground state
“Electrons occupies that lowest energy orbital”
- Based on the potential energy of each position
- n = 1 first → lowest energy
- then: 2s, 2p, 3s
What is the total number of electrons that can occupy the p sublevel? (3 points)
- 2 electrons
- 6 electrons
- 8 electrons
- 10 electrons
- 6 electrons
Select the words that correctly fill in the blanks for this statement:
The p sublevel has ________ orbitals that are ________-shaped. (3 points)
- three, dumbbell
- three, spherical
- five, dumbbell
- five, spherical
- three, dumbbell
Which of the following is not a possible sublevel? (3 points)
- 1s
- 2p
- 3f
- 4d
- 3f
Magnesium (Mg) has an atomic number of 12. What is the ground-state electron configuration of magnesium? (3 points)
- 1s21p62s22p2
- 1s21p61d4
- 1s22s22p63s2
- 1s22s22p62d2
3. 1s22s22p63s2
Which of the following is a reasonable ground-state electron configuration? (3 points)
- 1s22s22p63s2
- 1s22s22p63s23d4
- 1s22s22d102p3
- 1s22s22p32d6
- 1s22s22p63s2
The diagram shows four different locations in an atom.
Which locations are likely to have subatomic particles that are constantly in motion? (3 points)
- 1 and 2
- 2 and 3
- 1 and 3
- 2 and 4
- 2 and 4
A group of students designed a pamphlet. They used images and text to describe the chemical and physical changes that take place during cooking. Which type of scientific model did the students design? (3 points)
- An infographic because it helps visualize the molecular motion during the changes in nature.
- An infographic because the images improve understanding of the changes in matter.
- A graph because it shows interrelationship between two types of changes.
- A graph because it shows the effect of one variable on the other.
2. An infographic because the images improve understanding of the changes in matter.
The partial electron configuration of an atom with 11 electrons is shown.
1s22s22p6X
Which of the following does X represent? (3 points)
- 3s1
- 2d1
- 3p1
- 4s1
- 3s1
Define Coulomb:
abbreviated as C; unit of charge
What is Coulomb’s Law?
Coulomb’s law: the force between two charges is directly proportional to the product of the charges and inversely proportional to the square of the separation distance
Define Electric Field :
a region around a charged particle or object that applies a force on other charged particles or objects
Define Electric field lines:
a pattern of lines that point in the direction a positive charge would follow
Define Electrostatic Forces:
the attractive and repulsive forces between opposite or matching charges
What was Hund’s first rule?
orbitals within the same sublevel, with equal energy, are each occupied by one electron before any orbital in that sublevel is occupied by a second electron
What was Hund’s second rule?
electrons within the same orbital spin in opposite directions
Define Orbital notation:
a visual representation of electron configuration using lines and arrows for orbitals and electrons
What was Pauli exclusion principle?
no two electrons in the same atom can have the same set of four quantum numbers
What are the four parts of the Pauli Exclusion Principle?
- Principle Quantum Number (n)
- Angular Momentum Quantum Number (l)
- Magnetic Quantum Number (ml)
- Spin Quantum Number (ms)
What does the Angular Momentum Number indicate?
The sublevel/type of orbital
Define the following for n = 1:
- Name of subshells
- Angular Momentum Quantum Number
- Total electron in energy level
Subshell energy level: s
Angular Momentum Quantum Number: l = 0
Total electrons: 2
Define the following for n = 2:
- Name of subshells
- Angular Momentum Quantum Number
- Total electron in energy level
Subshell energy level: s, p
Angular Momentum Quantum Number: l = 0, l = 1
Total electrons: 8
Define the following for n = 3:
- Name of subshells
- Angular Momentum Quantum Number
- Total electron in energy level
Subshell energy level: s, p, d
Angular Momentum Quantum Number: l = 0, l = 1, l = 2
Total electrons: 18
Define the following for n = 4:
- Name of subshells
- Angular Momentum Quantum Number
- Total electron in energy level
Subshell energy level: s, p, d, f
Angular Momentum Quantum Number: l = 0, l = 1, l = 2, l = 3
Total electrons: 32
What is the Magnetic Quantum Number?
Represents the specific orbital an electron is likely to occupy
- The range of magnetic quantum numbers for a given sublevel (l) is from −l to +l.*
- For example, in an s sublevel (l = 0) there is only one available orbital. It has a magnetic quantum number of ml = 0. A p sublevel (l = 1) has three orbitals with magnetic quantum numbers of ml = −1, 0, +1. The orbital notation examples in the table show how the magnetic quantum numbers relate to the 3D shape, orientation, and number of orbitals in a sublevel.*
Define the following for s sublevel: ( l = 0)
- Magnetic Quantum Number
- Number of Orbitals
- Shape
- Magnetic Quantum Number: 0
- Number of Orbitals: 1
- Shape: spherical
Define the following for p sublevel: ( l = 1)
- Magnetic Quantum Number
- Number of Orbitals
- Shape
- Magnetic Quantum Number: -1, 0, 1
- Number of Orbitals: 3
- Shape: Dumbbell
Define the following for d sublevel: ( l = 2)
- Magnetic Quantum Number
- Number of Orbitals
- Shape
- Magnetic Quantum Number: -2, -1, 0, 1, 2
- Number of Orbitals: 5
- Shape: Double Dumbbell
Define the following for f sublevel: ( l = 3)
- Magnetic Quantum Number
- Number of Orbitals
- Shape
- Magnetic Quantum Number: -3, -2, -1, 0, 1, 2, 3
- Number of Orbitals: 7
- Shape: Multiple Lobes
What is the Spin Quantum Number?
A combination of other three Pauli Exception Principles is used to determine location of the electron
- first 3 quantum numbers → same orbital value
- 4th quantum number: Spin Quantum Number
- Identify the specific electron within the orbital
Hund’s second Rule:
Electrons within the same orbital spin in opposite directions
- 2 negatively charged electrons located near each other are most stable
- Option: +1/2 or -1/2
What is Orbital Notation Diagrams? How does it relate to Hund’s First Rule?
Hund’s First Rule:
Orbitals of equal energy are each occupied by one electron → spinning in the same direction
Arrows: (↑ ↓) used represent electrons
Example:
- Hydrogen → one electron found in 1st orbital → (↑)
- Helium → two electrons in first orbital → (↑ ↓)
- Lithium → three electrons (*two in first orbital and one in 2nd orbital) → *(↑ ↓) (↑)
What are electron Forces?
Electron charge:
- physical property of matter
- causes particle to experience force
- Electrostatic force creates electrical field
OPPOSITE forces = attract
SIMILAR forces = repel
What is atomic charge?
The electrostatic force between subatomic particles = massive
- influences arrangement
- electron spin: two electrons cannot spin in the same orbital spin
Electron >< Nucleus
Electron <> Electron
What is the electron force between atoms?
Neutral Atom: positively charged particles (protons) equals number of negative charged particles (electrons)
net charge: 0
When electron moved between atoms:
- one loses electron → a +1 charge
- gains electron → a - 1 charge
creates electrical charge between atoms
What is Coulomb’s Law of Electrical Forces?
Distance between charged particles decrease, force increases and visa versa
Force between two charges:
- directly proportional to product of charges
- inversely proportional to square of separation distance
Define Nuclear Charge:
Objects closer to each other / larger product of electrical charge = experience stronger electrostatic forces
- net positive charge associated with protons in nucleus → nuclear charge
- electrons close to the nucleus > n = 1
What was Democritus’s contribution to the periodic table?
- thought substances made up small items
- not broken smaller pieces
- indivisible unit
What was Aristotle’s contribution to the periodic table?
Fundamental elements: Earth, Fire, Water, Air
Mixed to create new materials → Alchemy
What was Robert Boyle’s contribution to the periodic table?
Scottish alchemist
Atoms are different sizes and shapes
What was Antione Laurent de Lavoisier’s contribution to the periodic table?
First modern definition of an element
Chemical substance not broken down into another substance
names 30 elements
Who was the first person to create a “periodic table” was understood today?
How was this accomplished?
First to create the “Periodic table” : Dmitri Mendeleyev
- noticed repeating pattern
- 1869
- Rows and columns
What are the differences between metals and non-metals?
Metals
- good conductors of electricity and heat
- solid at room temperature
- malleable, flexible, and ductile
- Shiny (lustrous)
- Higher density
- The elements toward the bottom left corner of the periodic table are the metals that are the most active in the sense of being the most reactive.
Nonmetals
- poor conductors
- Solid, liquid, or gas at room temperature
- Solids are brittle and break easily
- Dull
- Lower density
What are metalloids?
Properties of both metals and solid nonmetals
What are the 4 types of metals on the periodic table?
- Alkali Metals
- Alkaline Earth Metals
- Transition Metals
- Mixed
What are the differences between rows and periods?
Row: periods → same number of electron shells
Column: groups or families→ same number of electrons in outer shell
What are the three consecutive parts of this element called and what are these value’s purposes?
196.9665 u: Atomic Number
- Measured: atomic mass units (amu)
- comes from protons and neutrons
Au: Chemical Symbol
- (sometimes) first 1 or 2 letters
79: Atomic Number
- Arranged in this order
- Indicated the number of protons
What is the mass number?
not found on the periodic table
Counting the protons and neutrons in specific isotope of the element
round the atomic mass to the nearest whole number
How are the number of neutrons in an element determined?
Mass - Atomic Number
What are non-metals (on periodic table)?
Hydrogen, carbon, nitrogen, oxygen, fluorine, phosphorous, sulfur, chlorine, bromine, iodine, and selenium.
- brittle (when solid)
- not conductible
- not reflective
- dull
What are the properties of the alkali metals?
Group 01
- soft and shiny
- reactive
- mostly combined with other metals
What are the properties of the Alkaline Earth Metals?
beryllium, magnesium, calcium, strontium, barium, and radium.
- Harder and denser than Alkali metals;
- less reactive than Alkali
What are the properties of transition metals?
21-112 & Column 3-12
- Include: lanthanides and actinides
- special trait is their ability to transition in charge when they form ions
a. Lanthanide Series:
- soft, rare-earth metals
- transition metal category
- atomic numbers 57-71
- Known for silvery color
- hard to find in environment
b. Actinides Series:
- Human-made (not in nature)
- transition metals
- 89-103
What are the Lanthanide Series?
- soft, rare-earth metals
- transition metal category
- atomic numbers 57-71
- Known for silvery color
- hard to find in environment
What are the Actinides Series?
- Human-made (not in nature)
- transition metals
- 89-103
What are the Post Transition Metal group?
aluminum, gallium, indium, tin, thallium, lead, bismuth, and elements with atomic numbers 113 through 116.
- Opaque (milky)
- Solids
- not conductible
What are the Metalloids?
- boron, silicon, germanium, arsenic, antimony, tellurium, and polonium.*
- Properties of metals and nonmetals
What are the Halogens?
fluorine, chlorine, bromine, iodine, tennessine, and sometimes astatine, which is also considered a metalloid.
- non-metals
- reactive → easily bond multiple materials
- Can go through phase change at room temperature
What are the Noble Gasses?
helium, neon, argon, krypton, xenon, radon, and oganesson.
- Unreactive
- non-metal gases
How do isotopes (mass-wise) differ from elements?
same amount of protons
different amount of neutrons → different mass
Formula for Average Atomic Mass:
(percent abundance × mass) + (continue for each isotope) = average atomic mass
What are the two ways isotopes are represented?
- dash to the right of the name with the mass number (uranium-235)
- Mass number as superscript to upper left of the chemical symbol and place atomic number as a subscript
Mendeleev used his arrangement of elements in order of increasing mass and repeated properties to predict the mass and properties of undiscovered elements. (2 points)
True
False
True
Helium (He), oxygen (O), carbon (C) fluorine (F), and chlorine (Cl) are all nonmetals. Using the periodic table, which pair of nonmetals do you predict has the most similar properties, and why? (3 points)
- Oxygen and chlorine, because they are both alkalis
- Helium and carbon, because they are both noble gases
- Oxygen and fluorine, because they are in the same period
- Fluorine and chlorine, because they are both halogens
4. Fluorine and chlorine, because they are both halogens
A student observes that an element is shiny, bends easily, and can conduct electricity. What type of element is the student most likely observing? (3 points)
- Gas
- Metal
- Metalloid
- Nonmetal
2. Metal
Nickel has the chemical symbol Ni and the atomic number 28. How many protons, neutrons, and electrons would be found in an atom of nickel-78? (3 points)
- 28 protons, 28 neutrons, 50 electrons
- 28 protons, 50 neutrons, 28 electrons
- 50 protons, 28 neutrons, 50 electrons
- 50 protons, 50 neutrons, 28 electrons
2. 28 protons, 50 neutrons, 28 electrons
An atom has atomic number 5 and mass number 11. How many neutrons does the atom have? (3 points)
- 5
- 6
- 10
- 11
6
The image shows the representation of an unknown element in the periodic table.
Based on the representation, which of the following statements about the element is true? (3 points)
- The total number of protons plus electrons is 10.
- The number of neutrons in an atom of the element is 20.
- The sum of the masses of protons and neutrons is 20.1797.
- The mass of only the protons in the nucleus is 20.1797.
3. The sum of the masses of protons and neutrons is 20.1797.
Zinc has the chemical symbol Zn and the atomic number 30. How many protons, neutrons, and electrons does an atom of zinc-69 have? (3 points)
- 30 protons, 39 neutrons, 39 electrons
- 39 protons, 30 neutrons, 30 electrons
- 39 protons, 30 neutrons, 39 electrons
- 30 protons, 39 neutrons, 30 electrons
4. 30 protons, 39 neutrons, 30 electrons
An atom has atomic number 5 and mass number 11. How many protons does the atom have? (3 points)
- 5
- 6
- 10
- 11
5
The image shows the representation of an unknown element in the periodic table.
Based on the representation, which of the following statements about the element is true? (3 points)
- The number of neutrons in an atom of the element is 24.
- The combined mass of all the protons and electrons is 24.305.
- The combined mass of all the neutrons and electrons is 24.305.
- The mass number of the most common isotope of the element is 24.
4. The mass number of the most common isotope of the element is 24.
What relationship exists between protons and the atomic number?
Direct Relationship
What is an effective nuclear charge?
(Zeff) nuclear charge felt by outer shell electrons after considered the number of shielding electrons that surround the nucleus
Positions of electrons within atoms influenced by nucleus
- felt by outer shell electrons
- shielded by inner core electrons
What are electrostatic forces:
Forces between particles due to their electrical charge
- electrons repel each other
- proton and electron attract
Define “Screening constant:”
Value represents number by core electrons within atom
What is a nuclear charge?
Net positive charge of nuclear of atom
How is the nuclear charge felt by outer shell electrons determined?
Total nuclear charge - shielding (core) electrons
What are the [3] trends of effective nuclear charge across the periods of the Periodic table?
[1] Overall nuclear charge increase +1 → each additional proton
[2] Each atom:
- additional electron in outer energy
- number core electrons lower energy levels remain constant
[3] Screening constant stay the same
- Sulfur: zeff = +16 − 10 = +6
- Phosphorus: zeff = +15 − 10 = +5
What are the [2] trends of effective nuclear charge down groups of the periodic table?
- Protons increase down a group
- greater attraction between protons and outer shell electrons
- electrons pulled inwards
- Size of atoms and number of core electrons
- increase down group
- increase number of shielding electrons
What is the atomic radius?
Measured the size of an atom.
Measure the distance between nuclei of two bonded atoms of the same element and divide it by half
Distance between nuclei ÷ 2
What two trends are evident looking at atomic radii?
- Atomic radius increases moving down column/group
- Atomic radius decreases moving across the row from left to right
Define Ionization Energy:
the energy required to remove one electron from atom = positive ion
- elements with lower effective nuclear charge → less energy required to give up electron = less ionization energy
How does an increase in ionization energy compare to that of an effective nuclear charge?
Direct relationship
What are the trends of ionization energy on the periodic table?
- Increases from left to right and moving up a group on periodic table
- decreases down (as atom size increases)
What are the two types of Ionic Radii?
Electrons: subatomic particles gained or lost = ions
- Cations: positive charged + loss of electrons
- Anions: negative charge + gain of electrons
How do the ionic radii of metals and non-metals compare?
Metals: cations
smaller neutral atoms
losing one+ electron
Nonmetals: anions
larger than neutral atoms by gaining one+ electrons
What are the three trends of ionic radii on the periodic table?
- Decreases from left to right within metals
- Decreases from left to right in nonmetals
- Increases down a group
Define Electronegativity:
Measure the attraction of electron in chemical bond
- predict how elements and compounds interact during chemical reactions
- Higher → greater attraction
What is the relation between electronegativity and effective nuclear charge?
Elements with high effective nuclear charge: strong attraction outer shell → strong electronegativity
Direct relationship
On what scale is electronegativity measured?
Scale to measure: 0.0 → 0.4
- noble gasses > lowest
- Lowest on periodic table: (0.7) cesium (Cs) & francium (Fr)
Define Chemical Reactivity:
Readiness of substance to undergo chemical change
Compare Chemical Reactivity in metals and non-metals:
Metals:
- lowest in column → increased reactivity
- Right in row → decreased reactivity
Nonmetals:
- down column → decreased reactivity
- right in row → increased reactivity
Define Electron Affinity
the energy involved when neutral atoms gain electrons
- Take electrons → release energy (represented by negative value)
- Absorbs energy → accepts electron
not stable
loss electron spontaneously
What are the two Electron Affinity trends on the periodic table?
- More negative across period from group 1 to 17
relates to increase in effective nuclear charge
-
Not obvious moving down
(generally) more positive down a group
lot of exceptions
A cation is larger than it was as a neutral atom because the added electrons occupy a higher energy level. (4 points)
- True
- False
False
As you move down group one of the periodic table, what happens to the atomic radii? (4 points)
- They increase, because of the higher number of occupied energy levels.
- They increase, because of the stronger attraction between electrons and the nucleus.
- They decrease, because of the weaker effective nuclear charge.
- They decrease, because of the lower number of protons.
- They increase, because of the higher number of occupied energy levels.
Which of the following elements would you expect to have the lowest ionization energy value, and why? (4 points)
- Fluorine (F), because it is a halogen that naturally forms a negative ion
- Lithium (Li), because it has a low effective nuclear charge and large radius
- Neon (Ne), because it is a noble gas with a full energy level and small radius
- Nitrogen (N), because it is a nonmetal that does not have a full outer energy level
2. Lithium (Li), because it has a low effective nuclear charge and large radius
Where are the most reactive metals located? (4 points)
- Upper left of periodic table
- Lower left of periodic table
- Upper right of periodic table
- Lower right of periodic table
2. Lower left of periodic table
The image compares the arrangement of electrons in two different neutral atoms.
Which of the following best explains the position of the two atoms in the periodic table? (4 points)
- Both atoms have an estimated Zeff of 1; therefore, Atom D is to the right of Atom E in the same period.
- Both atoms have Zeff of 1; therefore, Atom D is above Atom E in the same column because of the additional energy level.
- Atom D has an estimated Zeff of 1 and is therefore to the left of Atom E, which has a Zeff of 9.
- Atom D has an estimated Zeff of 1 and is therefore below Atom E in the same column, which has a Zeff of 9.
2. Both atoms have Zeff of 1; therefore, Atom D is above Atom E in the same column because of the additional energy level.
Answer the following about Robert Boyle
- Contributions
- Innovations
- Further Studies
Chemist/Physicist (1627-1691), Ireland
Contributions:
- Inverse relationship between volume and pressure of gas
- Wrote first textbook about the study of substances
Innovations:
- Theorized that all matter & changes are due to particle motion
Further Studies:
- Behavior of gases and atomic theory
Answer the following about Joseph Proust:
- Contributions
- Innovations
- Further Studies
Chemist (1754-1826); France
Contributions:
- Water always has a two-to-one ratio of hydrogen to oxygen
Innovations:
- Law of Definite Proportions
- chemical compound will always have its own characteristic ratio of components
Further Studies:
- supported John Dalton
- Led to current atomic theory
Answer the following about Antoine Lavoisier:
- Contributions
- Innovations
- Further Studies
Chemist (1743-1794); France
Contributions:
- Metric system
- Rules for naming chemical compounds
Innovations:
- Law of Conservation of Mass
- chemical elements hold their mass in chemical reactions
Further Studies
- Numerous studies on matter & substance interaction
Answer the following about John Dalton:
- Contributions
- Innovations
- Further Studies
Chemist/Physicist/Meteorologist (1766-1844); England
Contributions:
- Meteorology
- Behavior of gasses
- Atomic theory
Innovations:
- Law of Particle Pressure:
- postulate for atomic theory
Further Studies:
- Atoms and sub particle studies
Answer the following about Marie and Pierre Curie:
- Contributions
- Innovations
- Further Studies
Chemist/Physicist (1867-1934)(1859-1906); Poland and France
Contributions:
- Elements emit energy at certain rate
- Pioneers in study of radiation
Innovations:
- Nobel Prize (shared with Becquerel) 1903 → discovered radioactivity
- Marie first women to win Nobel Prize for 2 difference sciences
Further Studies:
- radioactive materials
- uses in medical applications (X-rays)
Answer the following about Max Planck:
- Contributions
- Innovations
- Further Studies
Physicist (1858-1947); Germany
Contributions:
- Atoms consist of smaller particles
- Energy emitted in discrete units (quanta) not continuous waves
Innovations:
- Planck’s Constant
- quantum theory
- calculate energy and frequency
Further Studies:
- studies of atoms and sub-particles
- discovery photons
Answer the following about Ernest Rutherford:
- Contributions
- Innovations
- Further Studies
Physicist (1871-1937); England
Contributions:
- Demonstrated that atoms consist of tiny, dense, positively charged regions
Innovations:
- “Father of Nuclear Physics”
- discovered atomic nucleus
Further Studies:
- further studies by Bohr, Chadwick,
Answer the following about Neils Bohr:
- Contributions
- Innovations
- Further Studies
Physicist (1885-1962); Denmark
Contributions:
- Photons emitted from atoms
- Electrons exist in energy shell
Innovations:
- electrons have distinct energy levels
- light is emitted when electrons change energy levels
Further Studies:
- theorized atoms had positive charge and orbiting electrons
What contribution did Albert Einstein make to nuclear studies in 1905?
1905: Albert Einstein (German)
equation for nuclear power (E = mc2)
Explain how nuclear fission was discovered and by whom:
1938: Otto Hahn & Frizt Strassman (German) and Lise Meitner + nephew Otto Frisch (Sweden)
experiments with nuclear fission
Hahn and Strassman:
- shot elements with neutrons → uranium broken into two
- combined mass less than whole uranium
Meitner and Frisch:
- theorized that the loss of mass pointed to a splitting process released energy
- nuclear fission
What is the difference between Nuclear Fission and Nuclear Fusion?
Nuclear Fission
- Break apart → release energy
Nuclear Fusion
- Combining (fusing) atoms → even more energy
- joined nuclei two light elements
- reaction powers starts
Which of the following is a characteristic of durable scientific knowledge? (4 points)
- It remains unchanged over time.
- It is rarely subjected to examination.
- Several scientists’ investigations support it.
- Similar investigations yield dissimilar results.
3. Several scientists’ investigations support it.
Which of the following provides evidence to support Bohr’s theory of atomic orbitals? (4 points)
- Gold foil experiment
- Plum pudding model
- Spectrum of colors emitted by gas
- Radiation produced when beryllium is bombarded with alpha particles
3. Spectrum of colors emitted by gas
Which of the following observations indicates that there is a small, dense, positively charged part in the center of an atom? (4 points)
- Some uncharged particles are scattered by a gold foil.
- All uncharged particles are attracted towards a gold foil.
- All positively charged particles pass straight through a gold foil.
- Some positively charged particles bounce back from a gold foil.
4. Some positively charged particles bounce back from a gold foil.
The table compares the masses of three unknown subatomic particles.
Which particle is most likely present in the nucleus of the atom? (4 points)
- Only particle P
- Only particle Q
- Both particles Q and R
- Both particles P and R
4. Both particles P and R
The table shows the number of charged particles in an ion.
A negatively charged substance is brought near the ion. What will most likely happen and why? (4 points)
- The ion will repel the substance because it has more electrons than protons.
- The ion will repel the substance because it has more protons than electrons.
- The ion will attract the substance because it has more electrons than protons.
- The ion will attract the substance because it has more protons than electrons.
4. The ion will attract the substance because it has more protons than electrons.
What is the lowest point of a wave called? (4 points)
- Amplitude
- Crest
- Frequency
- Trough
4. Trough
Two friends at different locations want to communicate with each other by sending low energy signals. Which of the following methods can they use to communicate? (4 points)
- Produce x‒rays using colliding electrons and send them to radios, which capture sound.
- Send messages using infrared radiations, which travel in the form of waves.
- Send radio waves through intervening media like radio and television.
- Produce sound waves using microwaves from heated objects.
3. Send radio waves through intervening media like radio and television.
What term is used to describe the energy level of any level higher than the ground state of a particle? (4 points)
- Photon state
- Excited state
- Higher state
- Emission state
2. Excited state
An electron moved from a lower energy level to a higher energy level. What most likely happened during the transition? (4 points)
- A random amount of light was released.
- A fixed amount of energy was absorbed.
- A fixed amount of energy was released.
- A random amount of light was absorbed.
2. A fixed amount of energy was absorbed.
Define the principal quantum number. (8 points)
The principal quantum number (denoted by n) is one part of the Pauli Exclusion Principle (the other three are:
- the angular momentum quantum number (n),
- the magnetic quantum number (ml),
- the spin quantum number (ms)
The principal quantum number is used to indicate the energy levels that circle the nuclear.
- the symbol n starts at n = 1, which is the innermost, least energetic energy shell, and increases up until n = 7, which is the most energetic, and farthest from the nucleus.
- The principal quantum number can indicate what the other qualities of the electrons surrounding the nucleus of atoms; for example, if n = 1, then the angular momentum quantum number is l = 0, while the subshell is “s,” and there are 2 electrons in the energy level.
- The electrons in n = 2, n = 3, and n = 4, is 8, 18, and 32 respectively.
Therefore, the principal quantum number is used to denote the energy level an atom is in, which is used to determine the number and position of electrons in each energy level; however, according to the Heisenberg Uncertainty Principle, the position and velocity of a particle cannot be determined at the same time.
The table compares the number of electrons in two unknown neutral atoms.
Use this information to determine the number of valence electrons in the atoms. Which of the following correctly compares the stability of the two atoms? (4 points)
- Both are unreactive.
- Both are highly reactive.
- A is unreactive and D is reactive.
- A is reactive and D is unreactive.
1. Both are unreactive.
A substance is present in the gaseous state at room temperature. Which of the following best explains the probable position of the substance in the periodic table? (4 points)
- It is between groups 1 to 12 because it is a metal.
- It is between groups 13 to 18 because it is a metal.
- It is between groups 1 to 12 because it is a non-metal.
- It is between groups 13 to 18 because it is a non-metal.
4. It is between groups 13 to 18 because it is a non-metal.
Which of the following groups of elements are likely to have substances that have both metallic and non-metallic properties? (4 points)
- Actinides
- Group 18
- Lanthanides
- Group 14
4. Group 14
Describe the properties of alkaline earth metals. Based on their electronic arrangement, explain whether they can exist alone in nature. (8 points)
Alkaline earth metals:
- exist in Group 02 on the periodic table
- are extremely reactive (in correlation with the period trend that elements towards the bottom left are the most reactive).
Though they are similar to the alkali metals (Group 01), they are somewhat less reactive and denser and harder.
Their electronic arrangement makes them very reactive, meaning that they cannot exist alone in nature, but they are commonly found in compounds because they react easily.
For example, Magnesium (Mg) has 12 electrons, meaning that the first energy shell has 2 electrons. The second has 8 electrons, and the third (which will also require 8 to be stable) only has 2. Because the valence electron for Magnesium is only 2 (the more valence electrons there are, the most stable an element is), the element is highly reactive.
Since it is highly reactive, it is more likely to chemically bond with another element to create a compound, so few alkaline earth metals exist alone in nature.
Which of the following properties decrease down a column in the periodic table? (4 points)
- Effective nuclear charge
- Ionization energy
- Atomic radii
- Ionic radii
2. Ionization energy
Which of the following correctly compares the radii of Na and Na+? (4 points)
- Na has a smaller radius than Na+ because Na has expanded its electron cloud.
- Na has a larger radius than Na+ because Na has lost its outermost energy shell.
- Na has a smaller radius than Na+because Na+ has expanded its electron cloud.
- Na has a larger radius than Na+ because Na+ has lost its outermost energy shell.
4. Na has a larger radius than Na+ because Na+ has lost its outermost energy shell.
Which of the following explains how Marie and Pierre Curie tried to influence the use of their discovery? (4 points)
- They supported the use of radioactive elements in generating inexpensive power.
- They opposed the use of energy released during nuclear fission at the time of war.
- They supported the use of radioactive elements for medical diagnostic purposes.
- They opposed the use of nuclear fusion during the Manhattan Project.
4. They supported the use of radioactive elements for medical diagnostic purposes.
Which of the following is true for a reliable scientific source? (4 points)
- It cites logic.
- It cites opinions.
- It cites valid data.
- It cites common sense.
3. It cites valid data.
Which quantum number describes the subshell of an electron? (4 points)
- Spin quantum number
- Principal quantum number
- Magnetic quantum number
- Angular momentum quantum number
4. Angular momentum quantum number
How many orbitals are in the f sublevel? (4 points)
- 7
- 5
- 3
- 1
1. 7
How many electrons in an atom can have the quantum numbers n = 4, l = 0, ml = 0, ms = +1/2? (4 points)
- 1
- 2
- 3
- 6
1. 1
Describe the orbital diagram of an atom with 16 electrons. Explain how this orbital diagram demonstrates Hund’s rule. (8 points)
The first rule to consider for drawing an atom’s orbital diagram is the Aufbau Principle, which states the arrangement of electrons is as close to the nucleus as possible. Since there are 16 electrons, the configuration will look as follows: 1s22s22p63s23p4.
Furthermore, according to the Pauli Exclusion Principle, there will be 3 energy levels (n = 3), so the angular momentum quantum number will be l = 0, l = 1, l = 2 (the subshells will be s and p). Next, since there are three orbitals (energy levels), the magnetic quantum number will be -1, 0, and +1.
To determine the spin quantum number, Hund’s rules come into play. Hund’s first rule states that orbitals of equal energy levels are occupied by the same electron (which spins in the same direction), and it is denoted by arrows going up and down ( ↑ ↓ ). Therefore, since the atom has 16 electrons, it will look like this: ( ↑ ↓ ) ( ↑ ↓ ) ( ↑ ↓ ↑ ↓ ↑ ↓ ) ( ↑ ↓ ) ( ↑ ↓ ↑ ↓ _ _). Hund’s second rule states that electrons within the same orbital spin in opposite directions, which is seen in the above element since the last two electrons face opposite directions. Given that the last electron is spinning upwards, the spin quantum number is ms = -1/2.
