Group 7 elements

Question 1

What are the group 7 elements ?

Answer 1

Fluorine - a reaction yellow poisonous gas
Chlorine - fairly reactive, poisonous dense green gas
Bromine - a dense, poisonous red-brown volatile liquid
Iodine - dark grey crystalline solid or a purple vapour

They all exist as molecules which are pairs of atoms e.g. f2

Question 2

Trend of halogens as you go down

Answer 2

1) Become less reactive - harder to gain an extra electron because outer shell further from nucleus
2) higher mp bp
3) High RAM

7 electrons on outer shell so react in similar way

Question 3

Halogens can form ———- compounds

Answer 3

molecular

Halogen atoms can share electrons via covalent bonding with other non metals to get a full outer shell. For example HCL, PCL5, HF, CCLA4 Contain covalent bonds. The compounds that form when halogens react with non metals all have molecular structures.

Question 4

Halogen can form ——– ——- with metals

Answer 4

ionic bonds
Halogens form 1- ions = halides ( f- , cl-, Br-) when they bond with metals ( Na+cl- , Fe3+Br-3)
the compounds they form have ionic structures.

Question 5

What can occur between a more reactive halogen and the salt of a less reactive one

Answer 5

A displacement reaction
e.g. chlorines displace bromine and iodine from an aqueous solution of its salt and bromine displace iodine because of trend in reactivity