Atomic Structure Flashcards

1
Q

Describe the Bohr Model

A

Protons and electrons are found in the nucleus
Electrons orbit around the nucleus in shells / energy levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the relative mass of a proton, neutron and electron?

A

proton = 1
neutron = 1
electron = 1/1840

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the relative charge of a proton, neutron an electron?

A

proton = +1
neutron = 0
electron = -1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

define atomic number

A

the number of protons in the nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

define mass number

A

total number of protons and neutrons in the nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

define isotopes

A

atoms with the same number of protons but different number of neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

why do isotopes of the same element have the same chemical properties?

A

they have the same electron configuration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

define ionisation energy

A

the amount of energy needed to remove one mole of electrons from one mole of atoms, in the gaseous state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the units of ionisation energy?

A

kJ mol-1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what three factors influence ionisation energy?

A

nuclear charge
distance from the nucleus
shielding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

why is the second ionisation energy higher than the first?

A

second electron removed from an ion that already has a positive charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is an orbital?

A

a region within an atom that can hold up to two electrons with opposite spins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the highest energy electron?

A

outermost electron on an atom/ion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

why is the outermost electron the highest energy electron?

A

it is the furthest from the nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

when are d-block elements more stable?

A

when they have a full, or exactly half full subshell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the electron configuration of chromium?

A

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

17
Q

what is the electron configuration of copper?

A

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

18
Q

how does the ionisation energy change down a group?

A

atoms get bigger
more shielding
weaker attraction between nucleus and electron in outer shell
ionisation energy decreases down group

19
Q

state and explain the trend in atomic radius down a group

A

atomic radius increases
outer electrons are further away from nucleus, so they are less attracted to the nucleus

20
Q

why does the atomic radius get smaller from left to right across a period?

A

nuclear charge increases
greater attraction between the electrons and nucleus
amount of shielding stays the same

21
Q

what two factors does the mass spectrometer measure?

A

relative abundance
mass/charge ratio

22
Q

why are sample particles ionised in the mass spectrometer?

A

so they can be accelerated towards the negatively charged plate
so they generate a current when the hit a detector

23
Q

how is the ion accelerated in the mass spectrometer?

A

positive ions attracted to the negatively charged plate
all ions have the same kinetic energy

24
Q

how are ions separated in the flight tube in the mass spectrometer?

A

ions travelling at higher speeds (small m/z) move ahead of those travelling more slowly (large m/z)

25
Q

how are the ions detected in the mass spectrometer?

A

each ion hits the detector
ion gains an electron
generates a current
size of the current is proportional to the abundance of the ion1

26
Q

describe electron impact

A

sample is vaporised
high energy electrons fired at it from an electron gun
knocks off an electron
forming +1 ion

27
Q

describe electrospray ionisation

A

sample dissolved in volatile solvent
injected through fine hypodermic needle
attached to the positive terminal of a high voltage power supply
particles ionised by gaining a proton

28
Q

how do you calculate the Ar from mass spectrometry?

A

((mass 1 x abundance 1) + (mass 2 x abundance 2) + (mass n + abundance n)) / total abundance

29
Q

what is the equation for calculating kinetic energy of ions in the mass spectrometer?

A

KE = 1/2 x m x v^2

30
Q

what are the units for KE = 1/2 x m x v^2 and d = t x v

A

KE = J
m = Kg
V = m s-1
d = m
t = s

31
Q

how do you calculate the mass of an atom, in kg, using Avogadro’s constant?

A

mass number / 1000 / 6.022 x 10^23