Halogens

Question 1

What is a halogen?

Answer 1

Halogens are group 7 elements that are covalently bonded simple molecular substances.

Question 2

What are the trends in halogens?

Answer 2

All are diatomic
The colours get darker down the group
MP/BP increases down the group

Question 3

What colour and state is fluorine (F2) in and room temperature?

Answer 3

Very pale yellow
Gas

Question 4

What colour and state is chlorine (Cl2) in at room temperature?

Answer 4

Pale green
Gas

Question 5

What colour and state is Bromine (Br2) in at room temperature?

Answer 5

Brown
Liquid
Volatile, releases brown fumes

Question 6

What colour and state is Iodine (I2) in at room temperature?

Answer 6

Dark grey
Solid
Sublimes, releases purple fumes

Question 7

What colour and state is Astatine (At2) in at room temperature?

Answer 7

Black
Solid

Question 8

What do halogens form when they react with metals?

Answer 8

Ionic compounds

Question 9

What happens in the reaction between metal and halogens?

Answer 9

The outer shell electrons from the metal are transferred to the halogen.

Question 10

Halogens get _____ reactive as they go down the group.

Answer 10

Less

Question 11

All halogen atoms need to gain an electron to fill their outer-shell. This happens less easily down the group because:

Answer 11

Atoms have more electron shells
The extra electron is further from the nucleus
So it’s attraction to the nucleus is stronger

Question 12

What is the chemical test for chlorine?

Answer 12

Damp blue litmus —> turns white
This is because chlorine acts as a bleaching agent so removes the colour