MEDIUM
AS and A Level
IMPORTANT
Earn 100

By looking at the elements in Period 2 of the Periodic Table and using your knowledge of Period 3 elements, predict and explain the relative sizes of a nitride ion , and a fluoride ion, .

Important Questions on Periodicity
MEDIUM
AS and A Level
IMPORTANT
Why does sulphur have a lower melting point than silicon?

MEDIUM
AS and A Level
IMPORTANT
Why does sulphur have a higher melting point than chlorine?

MEDIUM
AS and A Level
IMPORTANT
Why is magnesium a better electrical conductor than phosphorus?

MEDIUM
AS and A Level
IMPORTANT
Why is magnesium a better electrical conductor than sodium?

MEDIUM
AS and A Level
IMPORTANT
What is the general trend in first ionisation energies across Period 3?

MEDIUM
AS and A Level
IMPORTANT
Explain why aluminium has a lower first ionisation energy than magnesium.

MEDIUM
AS and A Level
IMPORTANT
Explain why sulphur has a lower first ionisation energy than phosphorus.

MEDIUM
AS and A Level
IMPORTANT
The first ionisation energies of the p-block elements are given in the table below. Predict the missing value for the first ionisation energy of selenium.
p-block element of period 4 | Atomic number | First ionisation energy/ |
gallium | 31 | 577 |
germanium | 32 | 762 |
arsenic | 33 | 966 |
selenium | 34 | |
bromine | 35 | 1140 |
krypton | 36 | 1350 |
