1st lecture - atomic structure

Question 1

what is chemical reactivity determined by

Answer 1

the movement of electrons between atoms

Question 2

atoms cannot be

Answer 2

divisible
cannot be divided/separated

Question 3

atoms consist of

Answer 3

charged particles

Question 4

thompson made

Answer 4

plum pudding
electrons are the bits of plum

Question 5

rutherford model

Answer 5

electrons orbit the nucleus

Question 6

what was wrong with rutherfords model

Answer 6

• made it seem that all electrons are equal - challenged by atomic emission spectra

Question 7

how does atomic emission spectra challenge rutherford

Answer 7

in AES: electrons absorb energy and become excited

they transition to higher energy levels within the atom.

if rutherford was right, this would not happen as there would be no higher energy levels due to all e- being the same.

Question 8

what is the atomic emission spectra

Answer 8

spectra with different lines
light: wave or particle

excited e- transition to higher energy levels then return to their original levels by emitting energy in the form of photons (light)

Question 9

equation for energy carried by a photon

Answer 9

energy =
Plancks constant x frequency
=
planks x speed of light / wavelength

Question 10

planks constant

Answer 10

6.626 x 10^ -34

Question 11

what does the atomic emission spectra show

Answer 11

shows lines that are unique to each element

Question 12

what is E = hv tell us

Answer 12

eneegy = planks x frequency

photon energy isnt continuuous but quantised

its a multiple of “hv” meaning it has a discrete value

Question 13

bohr atom

Answer 13

positive nucleus
e- in orbits at diff distances to the nucleus

e- cannot exist between orbits, they are quantised

Question 14

what are orbits defined by

Answer 14

quantum number ‘n’

Question 15

e- closer to the nucleus are

Answer 15

lower in energy
tightly bound
more stable

Question 16

what is a transition

Answer 16

e- absorb energy
become excited
move to higher energy orbital
release energy in photons
relax back to original orbit

Question 17

what does each line on the spectra correspond to

Answer 17

a transition
this is unique to each element

Question 18

if an e- distance from the nucleus doubles (x2) the attraction

Answer 18

1/4s

greater distance = higher attraction

Question 19

equation to find energy released when an H electron moves to diff orbits

Answer 19

E =
-2.178 x 10^-18
x (1/nf ^2) - (1/ni ^2)

Question 20

how many orbitals are there in total

Answer 20

infinity

Question 21

as u move further from the nucleus, (increasing n value) the energy levels..

Answer 21

get closer and closer and closer

Question 22

n=1 series name

Answer 22

lyman series
UV light

1= bottom
lyman bc ur lying down at the bottom of the page

Question 23

n=2 series name

Answer 23

balmer series
VISIBLE light

2 ashy knees that need balm

Question 24

n=3 series name

Answer 24

paschen series
IR light

passion for Christ: father, son, Holy Spirit

Question 25

general rule for guessing which transition involved the greatest release of energy

Answer 25

the one with the lowest final n value eg: 1 or 2
this is bc the orbits are spaced out the most here

Question 26

which electron will emit a photon in the visible light spectrum

Answer 26

n=2
balmer series

Question 27

what is still wrong with the bohr explanation?

Answer 27

• works with H only tbh
• doesnt explain periodic properties of the periodic table
• atomic spectra results are different using a magnetic/non magnetic field

Question 28

electrons in magnetic field mass spectra

Answer 28

can make a transition to 3 slightly different energy levels

Question 29

electrons in atomic spectra with no magnetic field

Answer 29

can only absorb 1 distinct wavelength of light

can only jump 1 distinct energy level

Question 30

was planck studying waves or particles

Answer 30

waves

walk the Planck

Question 31

was einstein studying waves or particles

Answer 31

particles

Question 32

plancks equation for waves

Answer 32

energy = plancks constant x frequency

Question 33

is frequency a property of waves or particles

Answer 33

waves

Question 34

einsteins equation for energy

Answer 34

energy =
mass x speed of light^2

Question 35

de broglie equation

Answer 35

planks/wavelength = momentum

Question 36

wha does de broglie link

Answer 36

pure particle property and pure wave property.

combines planck and einsteins equations for particles and waves.

Question 37

what is constructive interference

Answer 37

when 2 waves are in phase with each other

they reinforce eachother and their amplitude doubles

Question 38

what is destructive interference

Answer 38

when 2 waves are out of phase and cancel each other out

Question 39

what property do electrons and light share

Answer 39

wave particle duality.
- constructive + destructive interference which is a property of waves.
- photoelectric effect: light knocks electrons off a metal - particle property

Question 40

summary of this set

Answer 40

e- have wave particle duality
meaning they have wave and particle properties

e- can move between orbits when energy is given these are called transitions and show up on atomic emissions spectra.