Chapter 13 Test Flashcards
Who was John Dalton?
Developed the first atomic theory; atom is a solid, neutral sphere
Who was JJ Thomson?
Discovered electrons; an atom is a solid, neutral sphere with embedded electrons.
Describe Thomson’s experiment.
He used a cathode tube with the rays bending at the negatively charged plates so he could tell they were negatively charged
Who was Ernest Rutherford?
Discovered nucleus with the gold foil experiment
Describe the gold foil experiment.
He had gold foil in between a red box and a detector. He noticed that 99.9% of alpha particles went straight through the foil to the detector. This was the first nuclear atomic model.
What were Rutherford’s conclusions from the gold foil experiment?
- Atoms are made of empty space
- There must be a small, dense, positive charge in atoms (the nucleus)
Who was Niels Bohr and what did he do?
Created the Planetary Model. Electrons travel in circular paths around the nucleus in their ground state. He stated that electrons have a minimal amount of energy that keeps them in orbit (ground state)
What is ground state?
The lowest, most stable energy state of an electron. Electrons do not go below ground state.
What is excited state?
Higher, less stable energy state of an electron
What is the Quantum Mechanical Model?
The modern stomic model/theory that describes the electronic structure of the atom as the probability of finding electrons within certain regions of space.
What can happen with electrons in the Quantum Mechanical Model?
They can move from one energy level to another. From stable states, they can gain energy from ground to excited states. They can go to a higher energy level and use more energy.
When is light produced?
When electrons gain normal, specific amount of energy called a quantum.
What happens when electrons gain quantums?
They leap from their ground state to their excited state. In their excited state, electrons are unstable and want to return to their ground state. To do this, the electrons must lose the same quantum of energy they gained. They lose this energy in the form of light and/or heat.
What happens when energy is released after it is lost in the quantum mechanical model?
Once the energy is released, the electrons return to ground state.
How many quantum numbers are there?
4
Compare incandescent bulbs and fluorescent bulbs.
In incandescents, electrons give lots of energy at excited state, which is very unstable so it not as efficient. Fluorescents use less energy because the gas is spread at a ground state, so they are more efficient when lighting large areas.
What equation is the Quatnum Model based on?
Schrodinger equation
What are the four quantum numbers?
Energy Levels, Subshells, Oribtals, Spins
What is the symbol for the energy level?
n
What is the symbol for the subshell?
L
What is the symbol for the orbital?
m
What is the symbol for the spins?
s
How many energy levels are there?
7
How many electrons can be held in each energy level?
1st-2 2nd-8 3rd-18 4th-32 5th-32 6th-18 7th-8
What is the formula for figuring out the number of electrons in an energy level?
2(n)^2
Describe subshells and their patterns.
Each energy level in made of 1-4 different energy states called subshells. These subshells explain the patterns electrons will travel in each energy level.
What are the four subshells?
s, p, d, f
What is the s-subshell?
The lowest energy subshell within any one energy level. It holds a maximum of 2 electrons. The electrons travel in a spherical pattern.
What is the p-subshell?
The second lowest energy subshell within any one energy level. It holds a maximum of 6 electrons. Their electrons travel in a figure-eight pattern.
What is the d-subshell?
The second highest energy subshell and can hold a maximum of 10 electrons. They travel in complex patterns.
What is the f-subshell?
The highest energy subshell and can hold a maximum of 14 electrons. They travel in very complex patterns.
How do electrons fill up subshells?
Lowest to highest energy
What is the order of filling for subshells by energy levels?
Diagonal up right, then below then to the right.
Draw out the table for filling order with the subshells.
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What are orbitals?
The space occupied by one pair of electrons, each subshell or a sublevel contains specific amount of orbitals that can be calculated by dividing the maximum number of electrons in any subshell and dividing by 2.
How many orbitals are held in each subshell when are full with electrons?
s-subshell-1
p-subshell-3
d-subshell-5
f-subshell-7
What shape are oribtals represented as?
square
What are the three subshell names in the p-subshell?
x, y, z
What are degenerate orbitals?
Orbitals of equal energy and they are orbitals within the same subshell
What is the Electron Cloud?
The sum of all electron orbital patterns in any subshell or in any energy level creates a spherical cloud called the electron cloud.
Draw the orbital diagrams for the s and p subshells.
Draw…
What is the purpose of electron spins?
To distinguish between the two electrons in an orbital, we need a 4th quantum number
What are electron spins?
The electrons in an orbital spin in either a clockwise or counterclockwise direction. One of the electrons in an orbital is arbitrairly assigned an s quantum number of -1/2. .
What are the two directions electrons spin in and why do they do this?
Clockwise and counterclockwise-designated because electrons are negatively charged and repel on each other, but because they have two directions of spin, electrons of opposite spin create oppositemagnetic fields allow electrons of opposite spin to come closer together and occupy an orbital.
What are unpaired electrons?
Also known as single electrons, when only one electron occupies an orbital.
What is the most stable form of orbital filling?
Full subshell (pairs of 2 in each orbital)
What is a half-full subshell?
1 electron in one direction in each orbital
What is a randomly filled subshell?
The least stable filling-any other filling than full or half-full orbitals.
What are the 3 Rules involving filling of the Atomic Orbitals?
- Aufbau Principle
- Pauli Exclusion Principle
- Hund’s Rule
What is the Aufbau Principle?
electrons enter orbitals of lowest energy first (subshells)
What is the Pauli Exclusion Principle?
No 2 electrons have the same 4 four quantum numbers (no 2 electrons are the same in terms of spin, subshell, energy level, and orientation).
What is Hund’s Rule?
Electrons fill orbitals of equal energy until all the orbitals contain one electron with a parrallel spin. Then once every orbital has one electon, electrons will fill each orbital with an electron of opposite spin.
What is the electron configuration for the f-subshell?
It is offest by 2 energy levels from its principle energy level
What is the electron configuration for the d-subshell
Offset by 1 energy level from the princple energy level
What are the D4 and D9 elements and what is their exception to electron configurations?
D4: Cr, Mo, W, Sg
D9: Cu, Ag, Au, Uuu
-Their exception is that their final s subshell gives one electron to their highest d subshell for more stability
Compare the Lewis Dot Diagram and the Electron Dot Diagram.
They both depict the valence electrons in an atom. They are in the outmost energy level of an atom. The Lewis diagram does not depict the electrons as s and p subshell electrons, just valences, whereas the Electron Dot Diagram depicts both groups and valences
How do Lewis Dot Diagrams fill up?
Go around clockwise singularly; after 4, they start pairs going clockwise from top
What is the electron dot diagram for group 1A?
One dot at top
What is the electron dot diagram for group 2A?
Two dots (one pair) at top
What is the electron dot diagram for group 3A?
One pair at top, single on the right
What is the electron dot diagram for group 4A?
Single dots on all four sides
What are the 4A exceptions to the electron dot diagram?
Tin and Lead-One pair at top, singles at right and bottom
What is the electron dot diagram for group 5A?
One pair at top, singles on other 3 sides
What is the electron dot diagram for group 6A?
Pairs on top and right, singles on bottom and left
What is the electron dot diagram for group 7A?
Pairs on all sides except left which has a single
What is the electron dot diagram for group 8A?
Full shell; four pairs
How did the Duality nature of Light lead to the Quantum Mechanical Model?
Light behaves as a wave, but light also behaves as a particle. The particle theory of light is what led to the quantum model.
What is the Wave Theory?
Light consists of electromagnetic waves (EM), which travel at a speed of 3.0 x 10^8 m/s
What is the symbol for speed of light?
c
What is the Electromagnetic Spectrum?
It includes types of electromagnetic radiation (EMR) arranged from high to low energy
List the types of waves in order from lowest frequency to highest.
Radio Radar Microwaves Infrared Visible Light Ultraviolent X-rays Gamma rays Cosmic rays
Explain the sun’s relationship with the color spectrum.
Sunlight consists of the full spectrum of colors which is referred to as stable light when passed through a prism, which light breaks into the various component colored light
What is the symbol for a wavelength?
/`\
What is an amplitude?
Distance from origin to peak of crest (maximum displacement from origin)
What is a wavelength?
The distance from a point on one wave to the corresponding point on an adjacent line.
What are common units for wavelengths?
Meters and millimeters
What is a photon?
The released quantum of light
What is frequency and what is its symbol?
nu (v)-the number of waves that pass a given point in a specific amount of time, usually a second
What is a Hertz?
(Hz)-how frequently something happens in one second
What are alternative units for Hertz?
s^-1, 1/s, Hz
At what speed do waves travel?
Speed of light
What is the speed of light?
3.0 x 10^8 m/s
What is the speed of light equation?
c=(/|)(v)
What is so special about wavelength and frequency?
They are inversely proportional
Who was Max Plank?
German scientist who developed a theory of energy emission called the Particle Theory of Light.
What did the first point of Plank’s energy emission theory consist of?
-Energy is given off in little packets of energy called quanta, instead of being given off continuosly like the wave theory
What did the second point of Plank’s energy emission theory consist of?
Quanta of radiant energy are called photons
What did the third point of Plank’s energy emission theory consist of?
The amount of energy given off is directly related to the frequency of light emitted.
What did the fourth point of Plank’s energy emission theory consist of?
His idea was that one quantum of energy was related to frequency by the equation: e=hv
What is Plank’s constant?
6.63 x 10^-34 J/Hz
What is the Plank equation?
energy (J)=h(Planks’) x v(frequency)
What is the photo electric effect?
This proved Planks’ theory. It is the ejection of electrons from a metal (usually an alkali metal) caused by light of a certain frequency-wavelength or energy.
What is threshold frequency?
Minimum frequency of light radiation needed to cause the ejection of electrons from a metal. Any frequencies below the threshold will not cause the loss of electrons.
What happens if you increase the intensity of light during threshold frequency?
More photons will come in and eject more electrons from the metal.
What is the emission spectrum?
The black background emits color light, fingerprint of where it emits light
What is the absorption spectrum?
A color background showing in black the spots were light is absorbed.
Describe how white light turns into the emisson/absorption sepctrum?
White light when mixed with sodium vapor and passed thorugh a prism becomes visible light, with black spots on its visible color spectrum line showing at which frequencies that the light has been absorbed.
How far do humans see in terms of measurement on the light spectrum?
Between 700 nm and 420 nm wavelengths
Who was DeBroglie?
He combined Einstein’s work with energy and matter with Plank’s work with light. He came up with an equation that could predict the wavelength of a particle acting as a wave.
What is the DeBroglie wavelength equation?
lambda=(Planks’)/(mass)(frequency)
Who was Heisenberg?
Stated that it is impossible to know the exact location and momentum of an electron at the same time. This statement is known as the Heisenberg Uncertainty Principle.
What is the Heisenberg Uncertainty Principle?
p(momentum)=m(mass) x v(velocity)
What is special about the Heisenberg Uncertainty Principle?
Mass remains constant, while velocity and momentum are interchangeable
Who was Schrodinger?
Treated the electron as a wave and developed a probablility calculation to determine the probability of finding electrons in certain areas.
Who used Schrodinger’s equation to calculate the chances of finding an electron in a certain space?
Max Born
