Wang Chem Quiz 3.1-3.4

Waves

light + sound travels in this form

Wavelength (λ)

distance between corresponding points on adjacent waves; si is meters

Frequency (ν)

the number of waves passing a given point per unit of time; si unit is 1/sec

Diffraction

special feature of waves

Electron Diffraction

experiment that proves electron are both particles + waves

Speed of light (c)

constant that is 3.00 x 10^8 m/s

Equation of relationship between wavelength + frequency

c = vλ; inversely proportional cuz c is always constant (3.00 x 10^8 m/s)

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radio waves, microwaves, infrared, visible light (starts w/red + ends w/purple), ultraviolet, x-rays, gamma rays; in order of decreasing wavelength; gamma rays have the highest frequency; radio waves have the highest wavelength

Energy

comes in packets called quanta, carried by photon (particle of light)

Formula for calculating the energy carried by a photon

E = hv; E = energy in Joules; h = Planck's constant of 6.626 x 10^-34 J * sec); energy is directly proportional to the frequency of radiation

Different elements have ___ emission spectra

different

Electrons

based on Bohr model, they orbit the nucleus on shells/energy levels; n=1 (first shell) is the closest to nucleus + has lowest energy level; the ones on higher shells are further away from nucleus + have higher energy; can jump between shells if getting/releasing energy

As the shell # increases, …

the distance between the shells + energy difference decreases

Ground state

lowest energy of an atoms; when electrons of an atom are orbiting on their normal shells

Excited state

when electrons absorb energy + jump to higher shells

When an electron absorbs energy

it goes up energy levels; later the energy is released (in form of light or emission spectra) + the e- goes down shells

Energy of light absorbed/released by electrons =

the difference in energy between 2 shells

Longer the distance electrons jumps …

the higher photon energy released/absorbed, the higher frequency of light, + shorter wavelength of light

Heisenberg's uncertainty principle

it's impossible to determine both the position + speed of an electron simultaneously; we can predict the possibility of an electron's position at a certain time

Principal quantum number

describes the energy level on which the orbital resides (an integer (whole #s + 0))

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4 types of subshells/sub energy levels; s p d f

s subshell

1 orbital + has spherical shape

p subshells

hourglass/bow kinda look

# of orbitals + e- in each subshell

orbitals: 1 in s, 3 in p, 5 in d, 7 in d; electrons: each orbital can hold 2 e- (s has 2e; p has 6e; d has 10e; f has 14e)

Energy-level overlapping

starts between 4s + 3d

Aufbau's principle

ground state electron configurations can be predicted by a strict set of rules; meaning 'filling up'; lowest potential energy in an atom is in 1s

Pauli exclusion principle

describes the restriction on the placement of electrons into the same orbital (opposite arrows in a box); if 2 electrons occupy the same orbital, they must have opposite spins

Hund's rule

describes how electrons are distributed among orbitals of the same sublevel when there is more than 1 way to distribute them; consists of 2 important ideas; at least 1 arrow facing up in each orbital of the sublevel before a second arrow (of the opposite spin) can drawn in the same orbital; if each orbital of the same sublevel has 1 arrow, all the arrows have the same spin

Noble gas configurations

a type of short-hand electron configuration which replaces core e- of atoms w/bracketed noble gas

Core electrons

always full-shell configuration

Lewis Dot Formula

each dot represents each valence e- + symbol represents the core e-

Electron Configuration of Cation

remove 1 e- for each positive charge

Electron Configuration of Anion

add 1 e- for each negative charge