The Structure of The Atom & The Periodic Table Flashcards
Learn about the structure of atoms & understanding the Periodic Table (132 cards)
1
Q
What is the basic structural unit of an element?
A
Atom
2
Q
What is the smallest unit of an element that retains the chemical properties of the element?
A
Atom
3
Q
Atoms consist of three primary particles. Name them.
A
Protons, neutrons, & electrons.
4
Q
What is a the name of the small, dense positively charged region in the center of the atom?
A
Nucleus
5
Q
The nucleus, small, dense, positively charged region in the center of the atom contains:
A
- Protrons (positively charged particles)
- Nuetrons (uncharged particles)
6
Q
What is the name of the negatively charged particles located outside of the nucleus of an atom?
A
Electrons
7
Q
These move very rapidly in a relatively large volume of space while the nucleus is small and dense.
A
Electrons
8
Q
Protons and electrons have charges that are equal in magnitude but….
A
Opposite in sign
9
Q
A ________ atom (no electrical charge) has the same number of protons and electrons.
A
Neutral
10
Q
What does the atomic number represent?
A
The number of protons in the atom.
11
Q
What does the mass number represent?
A
The sum of the number of protons and neutrons.
12
Q
True or false: The mass number usually listed to the left (upper left) of the symbol of the atom and above the atomic number?
A
True
13
Q
Number of protons + number of neutrons=
A
Mass number
14
Q
Mass number - number of protons=
A
Number of neutrons
15
Q
Mass number - atomic number =
A
Number of neutrons
16
Q
__________: atoms of the same element having different masses.
A
Isotopes
17
Q
What contains the SAME number of protons but DIFFERENT numbers of neutrons?
A
Isotopes
18
Q
Protons are the _________ number.
A
Atomic
19
Q
If you change protons, what changes?
A
The element.
20
Q
Isotopes of the same element have ___________ chemical properties.
A
Identical
21
Q
True or false: Some isotopes ARE radioactive.
A
True
22
Q
What does the number, 35.45, under Chlorine represent? (This number is located under the symbol of the element.)
A
It is the atomic mass. This is NOT the mass number of an isotope.
23
Q
True or false: The number under an element symbol is the mass number of an isotope.
A
False
24
Q
__________ ___________ is an average corrected by the relative amounts of each isotope present in nature.
A
Weighted average
25
Determining atomic mass:
- Convert % to a decimal fraction(divide % by 100).
- Multiply the decimal fraction by the mass of that isotope to determine the contribution of each isotope.
- Add the mass contributed by each isotope.
* Don't forget the units (amu)!!!
*Don't forget the units (amu)!!!
26
True or false:
Atomic mass determination.
Abundance ÷100 × mass(amu)= atomic mass
-then add all sums of each naturally occurring isotope.
True. You must round to significant figures BEFORE adding all of the sums together.
27
________ ________ ________ : the first experimentally based theory of atomic structure.
Dalton's Atomic Theory
28
6 Postulates of Dalton's Atomic Theory
1. All matter consists of tiny particles.
2. An aton cannot be created, divided, destroyed, or converted to any other type of atom.
3. Atoms of a particular element have identical properties.
4. Atoms of different elements have different properties.
5. Atoms of different elements combine in simple whole-number ratios to produce compounds (stable combinations of atoms)
6. Chemical change involves joining, separating, or rearranging atoms.
Postulates 1, 4, 5 & 6 are still regarded as true.
29
_________ were the first subatomic particles to be discovered using the cathode ray tube.
Electrons
30
True or false: Protons were discovered by Goldstein.
True. Protons are the same size charge but opposite in sign & is 1837 times heavier than an electron.
31
Neutrons = ______ charge
Zero
32
________ are 1837 times heavier than an electron.
Protons
33
_________ are almost the same mass as the proton.
Neutrons
34
Rutherford's "____ ____ __________" lead to the understanding of the nucleus.
Gold Foil Experiment
35
Rutherford's Gold Foil Experiment
- most of the atom is empty space.
| - the majority of the mass is located in a small, dense region
36
What is the study of information obtained from absorption or emission of light by atoms?
Spectroscopy. It is used to understand the electronic structure.
37
To understand the electronic structure, we must first understand light, which is the ......
Electromagnetic Radiation
38
Electronic Radiation
- travels in waves from a source
- speed of 3.0 × 10^8 m/s
True
39
Distance between 2 waves = _____________
Wavelength
40
The height of a wave = _____________
Amplitude
41
True or false: Each wavelength travels at the same velocity, but has its own characteristic energy.
True
42
____________ is the distance between identical points on successive waves.
Wavelength
43
Electromagnetic Spectrum
High energy = short wavelength [into 10^(-)]
Low energy = long wavelength [into 10^(+)]
True
44
The Bohr Atom
- atoms can absorb & enit energy via promotion of electrons to higher energy levels & relaxation to lower levels.
- energy that is emitted upon relaxation is observed as a single wavelength of light.
- spectral lines are a result of electron transitions between allowed levels in the atoms.
True.
45
Model of The Bohr Atom:
| Electrons exist in fixed energy levels surrounding the nucleus. This is....
Quantization of energy
46
Model of The Bohr Atom:
| Promotion of electron occurs as it absorbs energy is......
The Excited State
47
Model of The Bohr Atom:
| Energy is released as the electron travels back to lower levels is......
Relaxation
48
The amount of energy absorbed in jumping from one energy level to a higher energy level is a _________ _________.
Precise quantity
49
__________ what Bohr called the fixed energy level.
Orbit
50
What is the lowest possible energy state?
Ground state
51
True or false: In the Bohr Theory, electrons are found only in allowed energy levels.
True
52
Modern Atomic Theory:
- Bohr's model of the atom failed to explain line of spectra of atoms with more than one electron.
- One MAJOR change from Bohr's model is that electrons do NOT move in orbits.
- Atomic Orbitals- regionsin spacewith a high probability of finding an electron.
- Electrons move rapidly withinthe orbital giving a high energy density.
Modern Atomic Theory
53
________ _________- regions in space with a high probability of finding an electron.
Atomic orbitals
54
The physical and chemical properties of the elements are periodic functions of their atomic numbers is called ___________ _____
Periodic Law
55
Dmitri Mendeleev and Lothar Meyer- independently developed the precursor to our modern Periodic Table.
They noticed that as you list elements in order of atomic mass, there is a distinct regular variation of their properties.
56
Rows on a The Periodic Table are called ________
Periods (energy levels)
57
The columns on The Periodic Table are called _________
Groups
58
The far left column (Group 1) on the Periodic Table are ___________ metals.
Alkali
59
The second column (Group 2) are ____________ metals.
Alkaline
60
Groups 3- group 12 on the Periodic Table are _____________ metals.
Transition
61
Group 17 on the Periodic Table are ____________.
Halogens
62
Group 18 on the Periodic Table are ________ ________.
Noble gases
63
On the Periodic Table, atomic numbers 58- 71 are ____________.
Lanthanidee
64
On the Periodic Table, atomic numbers 90-103 are _____________.
Actinidee
65
True or false: Inner transition elements or rare earth elements are ( zoomed in from energy levels 6 &7 so you can see) located at the bottom of the Periodic Table.
True
66
Columns on the Periodic Table are called groups or also called ________.
Families
67
Classification of Elements:
__________- elements that tend to lose electrons during chemical change, forming positive ions.
Metals
68
Classification of Elements:
____________ - elements that tend to gain electrons during chemical change, forming negative ions.
Non-metals.
69
What are poor conductors of electricity?
Non-metals. They are dull/not shiny and will not shape.
70
What are high conductors of electricity?
Metals. They are shiny and malleable (hammered or pressed. You can beat into a shape)
71
____________ - have properties intermediate between metals and nonmetals.
Metalloids
72
True or false: ALL elements touching the zig zag line on the Periodic Table are metalloids.
False. All elements touching the zig zag line on the Periodic Table are metalloids EXCEPT for aluminum.
73
__________ _____________- describes the arrangement of electrons in atoms.
Electron configuration
74
__________ ___________- are the outermost electrons
Valence electrons
75
The Quantum Mechanical Atom:
Schröedinger developed equations that took into account the particle nature and the wave nature of the electrons.
True
76
Schröedinger's equations
Equations that determine the probability of finding an electron in a specific region in space, quantum mechanics.
- principle energy levels ( n= 1,2,3...)
- each evergy level has 1 or more sublevels or subshells (s,p,d,f)
- each sublevel contains 1 or more atomic orbitals
77
Energy Levels and Sublevels
True or false: The larger the value of n, the higher energy level and the farther away from the nucleus the electrons are.
True.
78
True or false: The number of sublevels in a principal energy level is equal to n.
True.
- in n=1, there is one sublevel
- in n=2, there are two sublevels
79
Principal Energy Levels
The electron capacity of a principal energy level (or total electrons it can hold) is 2(n)^2
True.
- n=1 can hold 2(1)^2= 2 electrons
- n=2 can hold 2(2)^2= 8 electrons
80
Principal Energy Levels
How many electrons can be in the n=3 level?
2(3)^2=18
81
_________ - a set of energy-equal orbitals within a principal energy level.
Sublevel
82
Subshells increase in energy. What are they?
s
83
True or false: True.
Subshell. Orbitals.
s. 1
p. 3
d. 5
f. 7
True.
84
Electron Configuration
What is the Aufbau Principle?
You can't get to 2s until you get 1s. Remember s
85
From Geiger's experiments, Rutherford concluded that the atom contains a small, extremely dense region in which most of the atom's ________ is concentrated. He called this central region the ___________ of the atom.
mass, nucleus
86
Radioactive isotopes have unique ____________ behavior but identical ___________ behavior to their nonradioactive counterparts, which allows them to serve as monitoring agents for biochemical systems.
nuclear, chemical
87
True or false:
| Atoms combine randomly to form compounds.
False. Atoms always combine in the same ratio to form a given compound.
88
True or false:
According to Dalton's Theory, chemical change involves separating, joining, or rearranging atoms.
True.
89
Light is also referred to as electromagnetic radiation and travels in the form of _________, but also has properties characteristic of ____________.
Waves, particles
90
Radiation from a particular point on the electromagnetic spectrum has a unique _____________, but all electromagnetic radiation travels the speed of light.
Wavelength
91
What is a wavelength?
The distance between identical points on two successive waves.
92
True or false:
| Atoms in the gas phase only emit radiation at specific wavelengths.
True. Each atom has a unique emission spectrum with radiation at specific wavelengths.
93
Energy can only have certain values and cannot have amounts between those values. This is referred to as the _____________ of energy.
Quantization
94
A spectral line in the emission spectrum of an atom represents .......
A photon of light being emitted when an electron moves from a higher energy state to the ground state of an atom.
95
True or false:
| An atomic orbital represents the probability of finding an electron in a region of space.
True.
96
A __________ is a substance whose atoms tend to lose electrons during chemical change.
Metal. On the other hand, a nonmetal is a substance whose atoms may gain electrons.
97
The modern ____________ law states that the physical and chemical properties of the elements display a certain periodicity related to their atomic ____________.
Periodic, numbers.
98
True or false:
| Elements in the same group of the periodic table have similar chemical properties.
True.
99
True or false:
The modern periodic law states that the physical and chemical properties of elements are periodic functions of their atomic numbers.
True.
100
All elements in Groups 1A to 8A of the periodic table are called the ________________ metals.
Main-group
101
Elements in the B groups are called the _____________ metals.
Transition
102
An _________ __________ is a specific region of a sublevel containing a maximum of two electrons.
Atomic orbital
103
What is the relationship that correctly describes the maximum number of electrons that each principal energy level can hold?
2(n)^2
104
A set of equal-energy orbitals within a principal energy level is called a ____________.
Sublevel.
105
An atomic ___________ is a specific region of space within a sublevel that can contain a maximum of ___________ electrons.
Orbital, two.
106
What requirement must be met for two electrons to coexist in the same orbital?
The electrons must have opposite spins.
107
Two electrons in one orbital that possess opposite spins are referred to as __________ electrons.
Paired.
| The number and arrangement of unpaired electrons in an atom are responsible for the magnetic properties of elements.
108
Aufbau Principle:
Electrons fill the lowest energy orbitals first.
109
Pauli's Exclusion principle:
Each orbital can hold up to two electrons with spins paired.
110
Hund's Rule:
When there is a set of equal-energy orbitals, each orbital becomes half-filled before any become completely filled.
111
Why are s,p,d, and f blocks designated as such?
The block designation indicates the subshell that is being filled with electrons.
112
In order to write the electron configuration of an atom, the number of _____________ must be known, and this number is equal to the atomic ____________ for a neutral atom.
Electrons, number.
113
Notation & meaning.
1s^2
1=
S=
2=
```
1= principal of energy
S= sublevel
2= number of electrons in a sublevel
```
114
The octet rule states that elements will react by gaining, losing, sharing electrons in order to attain the same electron configuration as their closest _____________ gas.
Noble
115
What are valence electrons?
The outermost electrons in an atom.
116
An ion with more electrons than its neutral atom is called a(n)
Anion
117
An ion with fewer electrons than its neutral atom is called a(n)
Cation
118
The charge of an ion with more electrons than its neutral atom is
Negative
119
The charge of an ion with fewer electrons than its neutral atom is
Positive
120
When forming an ion, a metal will ________ electrons and a nonmetal will _________ electrons in order to attain the same electron configuration as the closest noble gas.
Lose, gain.
121
True or false:
| Ions are formed by gain or loss of electrons.
True.
122
Recall the total electron capacities of the orbital types:
S: holds two electrons
P: holds six electrons
D: holds ten electrons
F: holds 14 electrons
123
Both transition metals and representative metals ___________ electrons when forming ions. However, transition metals differ from representative metals by forming ions of _____________ type(s) of charge(s).
Lose, multiple.
124
Facts:
- Positive ions (cations) are smaller than their parent atoms.
- The cation has more protons than electrons.
- The decrease in the number of electrons pulls the remaining electrons closer to the nucleus.
- Also, cation formation often results in the llss of all outer-shell electrons, resulting in a significant decrease in radius.
All true.
125
Facts:
- Negative ions (anions) are larger than their parent atoms.
- The anion has more electrons than protons.
- Owing to the excess negative charge, the nuclear "pull" on each individual electron is reduced.
- The electrons are held less tightly, resulting in a larger anion radius in contrast to the neutral atom.
All true.
126
Why does atomic size decrease from left to right across a row of the periodic table?
The number of protons in the nucleus increases, pulling the valence electrons closer.
127
True or false:
| Ionization energy increases from left to right as the number of protons in the nucleus increases.
True.
128
As atomic size decreases, ionization energy ______________,since 'the electrons are _____________ the protons in the nucleus.
Increases; closer to
129
Electron affinity measures the tendency of an element to form a(n) ______________.
Anion.
-Electron affinity measures the energy change associates with adding an electron to a neutral atom; i.e., forming an anion.
130
Facts:
- Electron affinities generally increase across a period.
- Novle gases have very low values for electron affinity. (Noble gases are very stable and do not readily form anions.)
True.
131
In the Bohr model of an atom, electrons only occupy certain allowed ___________ levels, or orbits. Atoms absorb or emit ___________ of light when electrons move between these levels.
Energy, photons.
132
Facts:
- Cathode rays consist of negatively charged particles.
- Cathode rays are identical no matter their source.
True.
