C1 - Group 7 Elements

Question 1

Properties of fluorine

Answer 1

Very reactive poisonous yellow gas

Question 2

Properties of chlorine

Answer 2

Fairly reactive poisonous dense green gas

Question 3

Properties of bromine

Answer 3

Dense,poisonous red brown volatile liquid

Question 4

Properties of iodine

Answer 4

Dark grey crystalline solid or a purple vapour

Question 5

What is common with all the group 7 elements?

Answer 5

They are all molecules(pairs of atoms) meaning that they are diatomic

Question 6

What are the trends as you go down the group 7 elements?

Answer 6

• Become less reactive ( harder to gain an extra electron,because the outer shell is further from the nucleus)
• Have higher melting and boiling points
• Have higher relative atomic masses

Question 7

What can halogens form with non-metals?

Answer 7

They form molecular compounds as they want to acheive a full outer shell ( HCL , PCI5 , HF and CCl4 contain covalent bonds). The compounds formed all have simple molecular structures

Question 8

What do halogens form with metals?

Answer 8

The form 1- ions which are called halides ( F- , Cl- , Br- and I- ) when they bond with a metal ( Na+Cl or Fe3Br-3+)

Question 9

How does a displacement reaction occur in group 7 metals?

Answer 9

A displacement reaction can occur between a more reactive halogen and the salt of a less reactive one.

(E.g chlorine can displace bromine and iodine from an aqueous solution of its salt ( a bromide or iodide) Bromine can also displace iodine because of the trend in reactivity )