chapter 3: vocab and definitions Flashcards
electromagnetic radiation
wave
regular oscillation in some particular property (position in the case of ocean waves)
frequency
number of waves crests passing a point in space in one second
wavelength
distance between successive wave crests
speed of light (c)
2.9979 * 10^8 m/s
photoelectric effect
electrons ejected from metal when light of sufficient energy hits it
photon
E of a photon
Planck’s constant
continuous spectrum
contains all wavelengths of visible light
line spectrum
each line corresponds to a discrete wavelength
rydberg-balmer equation
predicts the series of lines in an emission
the bohr model of the hydrogen atom
structural model in which an electron moves around the nucleus only in circular orbits, each with a specific allowed radius
what equation do you use to calculate the energy level of an electron transitioning from one energy level to another?
E = -2.178 * 10^18 J (1/nfinal^2 - 1/ninitial^2)
absorption spectra
observed when sample irradiated with electromagnetic radiation transitions when electrons jump from low to higher energy states
dual nature of light
wave properties and particulate properties
heisenberg’s uncertainty principle
momentum and position of particle-wave cannot be simultaneously known; the position of a moving electron cannot be precisely defined because they’re delocalized (spread out waves)
3d waves
orbitals (3 dimensional volume)
shape of an orbital represents
region of electron density around the nucleus
each orbital can hold
2 electrons max
n - principle quantum number
describes orbital energy and indicates distance of e- from nucleus
l - secondary quantum number
describes energy and shape of orbital; ranges from 0 to n-1
m of l - magnetic quantum number
describes orientation of orbital; ranges from +l to -l
m of s - spin quantum number
designates spin orientation of electron, “up” or “down”; can be +1/2 or -1/2
pauli exclusion principle
in a given atom no two electrons can have the same set of four quantum numbers; electrons in an orbital have opposite spins
polyelectronic atoms
atoms with more than one electron
variations in nuclear charge and number of electrons
change the magnitudes of the electrical forces that hold electrons in their orbitals
higher nuclear charge
higher attraction
shielding and penetration effect
electrons are shielded from nuclear charge by repulsion of other electrons
electron configuration
aufbau principle
as protons are added one by one to nucleus to build up elements, electrons similarly added to hydrogen–like orbitals
guidelines for atomic ground states
- each electron in an atom occupies most stable available orbital
- no two electrons can have identical descriptions
- orbital capacities are as follow
s - 2 electrons p - 6 electrons d - 10 electrons f - 14 electrons - higher n, less stable orbital
- for equal n, the higher l, the less stable orbital
hund’s rule
the lowest energy configuration for an atom is the one having the maximum number of unpaired electrons allowed by Pauli principle in a particular set of degenerate orbitals
valence electrons
electrons in the outermost principal quantum level of atom
continuous spectrum
electromagnetic radiation given off in an unbroken series of wavelengths
standing wave
localized wave phenomenon characterized by discrete wavelengths determined by the boundary conditions used to generate the waves; standing waves are inherently quantized
