Topic 1 Atomic Structure

Question 1

Mass of an electron

Answer 1

1/2000

Question 2

Ratio and mass of Cl isotopes

Answer 2

3:1
37:39

Question 3

Ratio of Br isotopes

Answer 3

79:81
1:1

Question 4

Relative atomic mass formula

Answer 4

(Abundance(mass)+abundance(mass))/total abundance

Question 5

What is the last high peak on a mass spectrum

Answer 5

Molecular ion (M)

Question 6

What causes the M+1 peak

Answer 6

Presence of the rare C-13 isotope

Question 7

What is spin-pairing

Answer 7

When two electrons occupy an orbital they spin in different directions

Question 8

In what way is the electron configuration of Chromium and Copper abnormal

Answer 8

An electron from 4s moves into 3d to form a more stable half full or full subshell

Question 9

Define ionisation energy

Answer 9

The enthalpy change for the removal of 1 mole of electrons from one mole of gaseous atoms to form 1 mole of gaseous 1+ ions

Question 10

Is ionisation energy exo or endo

Answer 10

Endothermic

Question 11

Three factors affecting ionisation energy

Answer 11

Shielding, nuclear charge, atomic radius

Question 12

Ionisation energy trend in a group

Answer 12

IE decrease - further from nucleus more shielding. Despite increase in protons. Less tightly attracted easier to remove requires less energy.

Question 13

IE across group trend?

Answer 13

Increase - similar shielding but more protons

Question 14

IE group 2-3 trend

Answer 14

Decrease higher energy subshell further from nucleus so more shielding despite proton increase

Question 15

IE group 5-6 trend

Answer 15

Decrease-Electron has to pair in a p orbital so mutual repulsion increases shielding

Question 16

Does atomic radius increase or decrease across a group

Answer 16

Decrease - more protons

Question 17

What is the standard molecule of P, S and Ar

Answer 17

P - P4, S - S8, Ar - Ar

Question 18

Standard states of Halogens?

Answer 18

Cl gas Br liquid I solid