HL Chemistry - Electron Configuration: Topic 3

electromagnetic spectrum

the range of frequencies or wavelengths of electromagnetic radiation

wavelength

distance between two consecutive peaks on a wave

frequency

the number of complete wavelengths that pass a point in a given time

when do the lines in a spectrum converge

high frequency, high energy, short wavelength

wavelength and frequency

inversely proportional

visible light

visible region of the electromagnetic spectrum

dispersion of visible light produces

colors ROYGBIV

gamma rays

electromagnetic waves with the shortest wavelengths and highest frequencies

infrared

electromagnetic waves of frequencies lower than the red of visible light.

ultraviolet

electromagnetic waves of frequencies higher than those of violet light.

xrays

electromagnetic waves having a wavelength shorter than ultraviolet radiation

dangerous electromagnetic waves

gamma, xrays, uv

speed of electromagnetic waves

are the same, what distinguishes them is their frequencies

speed of light

3.00 x 10^8 m/s

continuous spectrum

the emission of a continuous range of frequencies of electromagnetic radiation, all colors of spectrum

line spectrum

a spectrum containing radiation of only specific wavelengths

if energy increased in electrons, they

jump to the higher energy level

electron emits energy

returns to original energy level; depicts reversible process. gives off energy in the form of light in a photon

frequency of energy is the same

for both emission and absorption

excited state

higher energy, further from nucleus

ground state -> excited state

absorb energy, using heat or electrical discharge

excited state -> ground state

release energy (emission), electrons of specific frequency released, photon released

every element

produces unique line emission spectrum

bohr model

model of an atom that shows electrons in circular orbits around the nucleus

photons

particles of light

lyman series

set of spectral lines that appear in uv regions, final level when electron drops to n=1

balmer series

set of spectral lines that appear in visible light regions, final level when electron drops to n=2

paschen series

set of spectral lines that appear in infrared regions, final level when electron drops to n=3

speed = frequency x wavelength

c=fλ

energy = planck's constant x frequency

E=hf

orbital

a region in space within which there is a high probability of finding an electron

energy level numbers

n=1,2,3,4,...

sublevels

subdivisions of the energy level, exist in orders 1s, 2s, 2p, 3s, 3p, 4s, 3d...

each sublevel has

certain number of orbitals, maximum of 2 electrons in each

s orbital

2 electrons max, spherical

p orbital

6 electrons max, dumbbell shaped

d orbital

10 electrons max, complex clover shape

heisenberg uncertainty principle

states that it is impossible to determine both the position and speed of an electron in orbital with absolute certainty

hunds law

every orbital in a subshell is singly occupied with one electron before any one orbital is doubly occupied, and all electrons in singly occupied orbitals have the same spin.

pauli exclusion principle

an atomic orbital max two electrons, each with opposite spin direction

aufbau principle

when electron lost to form ion, the electron from highest principle number is lost first

electron configuration writing exceptions

cr (chromium) and cu (copper)

chromium electron configuration

1s2 2s2 2p6 3s2 3p6 4s1 3d5

copper electron configuration

1s2 2s2 2p6 3s2 3p6 4s1 3d10

half filled orbitals

stable because less repulsion

ionization energy

the amount of energy required to remove an electron from an atom

ionization energy reaction

endothermic and positive

lithium first ionization equation e.g.

Li (g) -> Li+ (g) + e

second ionization equation

Li+ (g) -> Li2+ (g) + e

higher ie value means

more energy required to remove electron

ie values depend on

magnitude of nuclear charge (higher proton number, stronger pull on outer electron). size of atomic radius (larger radius means electrons further from nucleus). shielding effect (more inner electrons shield outer electrons from nucleus)

as protons increase across a period

ionization energy increase

as electrons are one shell away, down a group

ionization energy decrease

electron in full shells

most stable

electrons in half filled shells

2nd most stable

repulsion between unbalanced orbitals

lesser stability

highest ie's

helium (loses from 1s2 and closest to nucleus), next is neon (from 2p6), next is argon (from 3p6).