Group 7 Elements The Halogens

What colour and state is chlorine at room temperature?

Green and a gas

What colour and state is bromine at room temperature?

Brown liquid and a orange gas

What colour and state is iodine at room temperature?

Dark grey solid and a purple vapour

Properties of the halogens?

• melting point increases as you down the group

• become less reactive as you go down the group

• become more dense as you go down the group

• become darker in colour as you go down the group

Colour and state of fluorine and astatine?

Fluorine is a yellow gas and astatine is a black solid

How do displacement reactions prove the reactivity of the halogens?

If a halogen displaces another halogen in a halide solution, it is more reactive.

Colour of chlorine in a solution?

Pale green

Colour of bromine in a solution

Orange

Colour of iodine in a solution

Dark brown

What happens when you add Potassium Bromide to chlorine?

The chlorine would displace the bromide ions as it is more reactive, and the solution would turn pale green to orange

What happens when you add Potassium Iodide to bromine?

The bromine would displace the iodide ions as it is more reactive, and the solution would turn orange to dark brown

What happens when you add Potassium Iodide to chlorine?

The chlorine would displace the iodide ions as it is more reactive, and the solution would turn pale green to dark brown

What is the trend in reactivity of group 7 in terms of electronic configurations?

The reactivity of group 7 non-metals decrease as you go down the group. This is because halogens react by gaining an electron, and as you go down the group the atoms become bigger, and the distance between the nucleus and the outer shell is larger, so therefore the force of attraction is weaker and it is harder to attract a near by electron. Therefore, it is less reactive.