CHEM 177 : EXAM 3
29 Cards in this Set
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Thermodynamically Favored
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Likely to occur on its own due to thermochemical properties.
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Spontaneous
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Energy must be imparted to get the reaction started.
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Entropy
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The randomness in a system or the extent to which energy is distributed or dispersed among the various motions of the molecules of the system.
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Electronic Structure
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The arrangement of electrons in an atom or molecule.
The number of electrons in an atom and the distribution of the electrons around the nucleus and their energies. 6.1
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Light
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Consists of regularly oscillating magnetic and electrical fields.
Visible, infrared, ultra-violet, and x-ray light. 6.1
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Electromagnetic Radiation
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A form of energy that has wave characteristics and that propagates through a vacuum at the characteristic speed of 3.00 x 10^8 m/s.
Visible light, radio waves, infrared radiation, and x-rays. 6.1
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Wave
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A wave is a disturbance that propagates through space and time, usually with transference of energy.
6.1
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Wavelength (λ)
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The distance between two adjacent peaks.
λ = c/ν 6.1
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Frequency (ν)
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The number of complete wavelengths, or cycles that pass a given point each second.
ν = c/λ 6.1
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Speed of Light
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3.00 x 10^8 m/s
c = ν*λ 6.1
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Photon
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Particle of light
E = h*ν 6.2
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Quantization
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The energy in discrete energy packets, not continuous.
6.2
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Quantum
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The smallest quantity of energy that can be emitted or absorbed as electromagnetic radiation.
6.2
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Line Spectra
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When atoms of a particular element excited (heat, electrical discharge) discrete colors are emitted rather than a rainbow.
6.3
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Ground State
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The lowest energy state. n=1
6.3
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Excited State
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When the electron is in a higher energy orbit.
n=2 or higher. 6.3
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Bohr Model
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Depicts the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus.
6.3
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DeBroglie Equation
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λ=h/mv
v=velocity mv=momentum h=Planck's constant 6.4
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Electron Density Distribution
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Result of calculation showing where it is likely to find electrons.
6.5
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Principle Quantum Number (n)
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1,2,3, etc.
As n increases, the orbital volume increases, electron exists further from nucleus on average, electrons less tightly bound. shell/level 6.5
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Azimuthal Quantum Number
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l
1,2,3...n-1 defines the shape of the orbital sublevel 6.5
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Magnetic Quantum Number
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ml
values between L and -L indicates orientation of orbital in space specific orbital 6.5
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Electron Spin
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Electrons behave as if they spin on their axis-giving rise to a magnetic field.
6.5
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Spin Quantum Number
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ms
1/2 or -1/2 spin up or spin down electronic spin 6.5
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Pauli Exclusion Principle
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each electron in an atom has a unique set of quantum numbers: n, l, ml, and ms.
No two electrons in an atom can have the same set of 4 quantum numbers. 6.7
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Hund's Rule
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For degenerate orbitals, the lowest energy is attained when the number of electrons with the same spin is maximized.
Parallel spins 6.8
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Degenerate Orbitals
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orbitals at identical energy levels.
6.8
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Valence Electrons
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Electrons involved in chemical bonding
All outer shell electrons 6.8
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Core Electrons
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Inner shell electrons
6.8
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CHEM 177: CHAPTER 1