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26 Cards in this Set
- Front
- Back
Quantum Numbers:
n= ? What does it describe? |
n= 1,2,3...
Shells, higher shell number means a greater distance away from nucleus. |
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Quantum Numbers:
l=? what does it describe? |
l = 0,1,2,n-1
Angular momentum quantum number, shape of electron's orbital. |
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Quantum Numbers:
m(l)= ? What does it describe? |
M(l) = ...-L,-1,0,1,L..
magnetic quantum number, orientation of orbitals in space. s-> L=0 p-> L=1 d-> L=2 |
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Aufbau Principle
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Electrons placed in orbitals, subshells, and shells in order of increasing energy
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Pauli Exclusion Principle
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Within an atom, no two electrons can have the same set of quantum numbers.
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Hund's Rule
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Electrons always occupy an empty orbital first...singly, then pair up only if no empty orbitals are avaliable.
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Formula: Energy of an Electron
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E(n) = (1/n^2)(-2.178x10^(-18)) joules
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Electromagnetic radiation
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Electrons jump to higher energy levels, when drop, it gives off energy in the form of this radiation.
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Formula: Energy and Electromagnetic Radiation
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delta E = hf = hc/lambda
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planck's constant
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6.63x10^(-34) Joule-sec
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speed of light
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3.00x10^8 m/sec
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Dalton's elements
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first to say that there are many different kinds of atoms, which combine to form compoundds and same ratio of elements
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Dmitri Mendeleev and Lothar Meyer
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development of periodic table
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Thomson's Experiment
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deflection of charges in a cathode ray tube, atoms are composed of positive and negative charges. Plumb pie model.
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Milikan's Experiment
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oil drops in electric field to calculate charge of an electron
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Rutherford's experiment
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fired alpha particles at gold foil. Positive chare concentrated in center.
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Max Planck
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electromagnetic energy is quantized, so energy changes do not occur smoothly but in small specific steps.
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Bohr model
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electrons orbit at a specific fixed radii, only works for hydrogen
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Heisenberg uncertainty principle
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impossible to know both the position and momentum of an electron at a particular instant.
An electron orbital is a probability function describing the possibility of an electron at a location. |
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de Brodlie hypothesis
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all matter has wave characteristics.
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De Broglie equation
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lambda= h / mv
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Atomic radius...
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decreases across a period
increases down a group |
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Size of ions...
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Cations smaller than atoms
Anions bigger than atoms |
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Ionization energy
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Energy required to remove an electron from an atom
increases across a period decreases down a group |
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Electron affinity
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measure of the change in energy of an atom when electron is added.
Energy put in when atom becomes less stable...vice versa |
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Electronegativity
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how strongly nucleus of an atom attracts electrons of other atoms in a bond
Increases across period Decreases down a group |