Atomic structure

Question 1

What is relative atomic mass?

Answer 1

Ratio of the average mass of one atom of an element to 1/12 of the mass of an atom of carbon-12

Question 2

How many orbitals does each sub shell have?

Answer 2

Half the max electron number
Eg s has max 2 electrons so 1 orbital

Question 3

Where does 4s and 5s go?

Answer 3

3p, 4s, 3d, 4p, 5s, 4d

Question 4

What are 2 exceptions to the general configuration rule?

Answer 4

Chromium and copper

Question 5

Configuration of chromium

Answer 5

[Ar] 4s1, 3d5

Question 6

Configuration of copper

Answer 6

[Ar] 4s1, 3d10

Question 7

What parts of the periodic table are s, p, d, f?

Answer 7

S: before transition metals
P: elements after transition metals
D: transition metals
F: under transition metals

Question 8

Formula for number of electrons in each shell

Answer 8

2n squared

Question 9

Size of an electron

Answer 9

0.0005

Question 10

No. Of electrons in s subshell

Answer 10

2

Question 11

No. Of electrons in p subshell

Answer 11

6

Question 12

No. Of electrons in d subshell

Answer 12

10

Question 13

No. Of electrons in f subshell

Answer 13

14

Question 14

How can you tell if an element is a transition metal from its configuration?

Answer 14

Partially filled d orbitals
Eg [Ar] 4s2 3d8 is a transition metal but [Ar] 4s2 3d10 would not be as 3d10 is full

Question 15

2 things ToF finds?
What 2 things does this help calculate?

Answer 15

•Mass and abundance of isotopes
•Ar & Mr

Question 16

2 types of ionisation

Answer 16

Electron impact
Electronspray

Question 17

Equation for electron impact

Answer 17

X (g) + e- —> X+ (g) + 2e-

Question 18

What is the electron impact process?

Answer 18

(Bang bang)
Fire electrons to knock off atom’s electron

Question 19

What is the electron spray process? (4 points)

Answer 19

• Dissolve in volatile solvent
• Apply high voltage
• Inject thru hypodermic needle as spray into ionisation chamber
• Gains proton and evaporates

Question 20

Electron impact/ Electron spray is used for what size molecules?

Answer 20

Impact: SMALL
Spray: BIG

Question 21

What molecular ions travel fastest?

Answer 21

Smallest/Lightest ones

Question 22

Electron spray equation

Answer 22

X (g) + H+ —> XH+ (g)

Question 23

Technique of Tof (broken into 6 parts)

Answer 23

•Inject sample
•Vaporise
•Ionise
•Accelerate (using electric field)
•Ion drift
•Detector (produces a current when hit with ions)

Question 24

How to convert g/mol (what periodic table is in) to kg for KE equation

Answer 24

Divide by (1000 x Avogadros constant)

Question 25

What is size of current proportional to?

Answer 25

Number of ions

Question 26

What mass unit are all elements in the PT in?

Answer 26

g/mol

Question 27

What does mass spectra show?

Answer 27

Abundance of isotopes/fragments in a sample and their ratios

Question 28

M/z

Answer 28

Mass/charge So basically just mass as charge=1

Question 29

What are the smaller peaks on a mass spectra caused by? How do you calculate their m/z values?

Answer 29

Fragments Sum of the involved isotopes’ masses

Question 30

What is 1st ionisation energy? (2 points)

Answer 30

• energy required to remove 1 e- from each atom in 1 mole of gaseous atoms • and produce 1 mole of 1+ gaseous ions

Question 31

What effect does removing electrons have on ions? Why?

Answer 31

Atomic radius gets smaller As there are more protons than electrons to pull in electrons

Question 32

What 3 factors affect ionisation energies?

Answer 32

Atomic radius No. of protons Shielding (no. of shells)

Question 33

When atomic radius increases, what happens to nuclear attraction?

Answer 33

decreases

Question 34

When number of protons increases, what happens to nuclear attraction?

Answer 34

increases

Question 35

When shielding (inner electrons repelling outer ones) increases, what happens to nuclear attraction?

Answer 35

decreases

Question 36

Down a group, ionisation energy...

Answer 36

decreases

Question 37

Across a period, ionisation energy...

Answer 37

increases

Question 38

Why are there dips in ionisation energy when going across a period? (3 reasons)

Answer 38

if there is 1 electron in an orbital, it's easier to remove increase in subshell shielding if 2 electrons are paired up in an orbital, it's easier to remove (they repel each other)

Question 39

True or false: group 1 has higher overall ionisation energies than group 0

Answer 39

False- group 0 have full outer shells, so requires more energy than group 1

Question 40

Why is there jumps in successive ionisation energies?

Answer 40

There is a jump every time electrons start to be removed from a new, lower shell