The Periodic Table - Group VII properties

Front

Which group do the elements chlorine, bromine and iodine belong to? What is another name for this group of elements?

Back

Group VII, the halogen

Front

Halogens are diatomic. What does this mean?

Back

They form molecules consisting of 2 atoms.

E.g. Cl₂, Br₂, etc

Front

What is the colour and state of chlorine at room temperature?

Back

Pale green gas

Front

What is the colour and state of bromine at room temperature?

Back

Red-brown liquid

Front

What is the colour and state of iodine at room temperature?

Back

Grey-black solid

Front

Why are the halogens at different states at room temperature? What is the trend down the group?

Back

At room temperature, chlorine is gaseous, bromine is liquid and iodine is solid because they have different melting and boiling points. As you go down the group, melting and boiling point increase.

Front

What state would you expect the halogens fluorine and astatine to be at room temperature?

Back

Fluorine is above chlorine so should have a boiling point lower than chlorine. This means it would be a gas at room temperature.

Astatine is below iodine in Group VII so should have a higher melting point than iodine. Therefore you can predict that it would be a solid at room temperature.

Front

What is trend in colour and density of the Group VII elements?

Back

Colour gets darker down the group.

Density increases down the group.

Front

Why do melting and boiling point increase down Group VII?

Back

The molecules get bigger down the group so there are stronger intermolecular forces to overcome during melting / boiling so more energy is required to change state.

Front

When does a halogen displacement reaction occur?

Back

When a more reactive halogen displaces a less reactive halogen from an aqueous solution of its halide ions.