1: Atomic Structure and the Periodic Table

Question 1

Mass spectrometer equation for RAM based on %abundance

Answer 1

RAM = Σ(isotopic mass * %abundance) / 100

Question 2

Mass spectrometer equation for RAM based on relative abundance

Answer 2

RAM = Σ(isotopic mass * relative abundance) / total relative abundance

Question 3

How do mass spectometers work

Answer 3

• Particles are given a charge and then passed through a magnet/electric field
• The resulting path of the ions depends on their m/z ratio
• Particles with a large m/z ratio are deflected least

Question 4

First ionisation energy definition

Answer 4

The energy required to remove the first electron from each atom in one mole of atoms in the gaseous state

Question 5

Factors affecting ionisation energy

Answer 5

• Nuclear attraction
• Atomic radius
• Electron shielding

Question 6

Reason for increase in successive ionisation energies

Answer 6

The positive ions formed increases the attraction on the remaining electrons

Question 7

Trend in 1st i.e. across a period

Answer 7

Increase as the number of protons increase but there is no extra shielding

Question 8

Trend in 1st i.e. down a group

Answer 8

Decrease as there is more shielding

Question 9

What is the atomic emission spectra

Answer 9

• Unique spectra of light emitted by an element when electricity is run through it
• Caused by electrons gaining energy and moving up a shell, and then emitting the energy as light when they move down again

Question 10

Order of electron sub-shells

Answer 10

1s > 2s > 2p > 3s > 3p > 4s > 3d > 4p

Question 11

Exception to the trend of ionisation energy

Answer 11

• Slight drop between 2 and 3 as its easier to remove from 3p than 3s
• Slight drop between group 5 and 6 as paired up electron repulse each other