Group VII metals - halogens

Question 1

Down the group, the melting point and the boiling point…

Answer 1

Increases
1. halogens have weak intermolecular forces between the molecules
2. Down the group, the molecules are larger and heavier (Mr increases)
–> strength of Van der Waals’ forces between molecules increases

Question 2

Down the group colour intensity…

Answer 2

Increases
Fluorine - Pale yellow gas
Chlorine - Greenish-yellow gas
Bromine - Reddish-brown liquid
Iodine - Shiny black crystal; violet gas

Question 3

Halogens are very reactive.
Down the group, the reactivity…

Answer 3

Decreases
attractive forces of the nucleus on electrons is further away and thus weaker
–> harder for atoms to attract electrons

Question 4

Displacement reaction

Answer 4

A more reactive halogen can displace a less reactive one from its salts.