Electrons and stuff

two types of forms of energy

wave and particles

collision in waves

waves can interact thru constructive and destructive interference

constructive interference

waves combine and get bigger then return to the original size

destructive interference

waves overlap out of phase and cancel each other out or make a weaker, smaller wave

diffraction

waves bend or spread out as they pass through a small opening

photoelectric effect

certain colors cause electrons to come off metal, others do not

how does light act like a wave

spreads, interferes, and diffracts like a wave

quantize

to make something jump between steps instead of changing smoothly

quantum theory

energy comes in tiny indivisible packets called quanta or photons

energy can only be added or taken away in samll exact amounts, number multiples of hv

continuous spectrum

contains all wavelengths of a visible light

light with highest frequency

gamma rays

type of light with lowest frequency

radio waves

line spectrum

contains specific wavelengths of light, discontinuous

quantized model

electrons orbit nucleus in fixed paths (energy levels/shells)

each energy level (n) has a specific radii, quantized

Niels Bohr’s postulates for an atom

1. electrons can only exist in certain energy levels, not in between

2. shells closer to the nucleus are more stable

3. electrons can absorb a photon with exactly the righta mount of energy that would put it in a higher level

   1. electrons in excited state will emit photons when they spontaneously drop to lower energy levels

ground state

lowest possible energy state for an atom

E photon eq

E_{last energy level} - E_{initial energy level} = hv

valence shell

outermost principal energy level with electrons

valence electrons

electrons in valence shell

Louis de Brogie wave

particle duality

particle duality

particles that are very small have wave-like characteristics

relation btwn wave-like properties and particle mass

inversely varied

what does the double slit experiment work with besides light

electrons

DeBroglie’s theory

energy levels in an atom exist as standing waves of specific wavelengths

Heisenberg’s uncertainty principal

you cannot know everything about something at the same time with accuracy

if you try to measure exactly where a particle is, you’ll lose accuracy in momentum measurement → you can’t determine energy and location at the same time

orbital

region where there is a high probability of finding electrons at a given energy level

modern atomic model

shows most probably location of an electron (orbital)

quantum

a photon

principle quantum number n

shell number, must be a whole number

relationship between value of n and energy

the larger the value of n, the larger the orbital and the higher the energy

sublevels

each energy level has 1 or more sublevels

2nd quantum number

determines shape of orbital

examples of 2nd quantum number

l = 0 (s), l = 1 (p), etc

why are s orbitals spherical

the probability is the same distance in all directions

subshell

group of orbitals within the same shell that have the same energy and shape

example of subshells

s, p, d, f

magnetic (3rd) quantum number

ml, describes orientation of orbital in space

does orientation affect amount of energy

no

order for filling electrons

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, etc

Pauli exclusion principle

an orbital can be occupied by a max of 2 electrons with opposite spins

lowest amount of electrons in an orbital

0

what does aufbau mean

building up

aufbau principle definition

electrons occupy orbitals in order of higher energy, filled from the bottom

hund’s rule

fill each orbital in a sublevel singly before doubling up

diagmagnetic orbital

contain only paired electrons, not attracted to magnets

paramagnetic particles

contain one or more unpaired electrons, weakly attracted to very strong magnets

condensed electron configuration laws

1. find the elemnt on the periodic table

2. find the nearest noble gas that comes before the element

3. write that noble gas in brackets

4. add remaining electrons after the noble gas

three ways to represent orbitals in a diagram

1. orbital diagram

2. electron config

3. shell config