Predicting Chemical Reactions (OCR Gateway GCSE Chemistry)

This question is about elements in the Periodic Table.

Look at the table. It shows some properties of Group 7 elements.

Complete the table. Use ideas about trends down a Group to help you.

In the table, the Group 7 elements are listed in order of reactivity.

The equations show a displacement reaction of Group 7 elements.

Group 1 is another group of elements in the Periodic Table.

[1]

This question is about the properties of elements in Groups 1, 7 and 0.

Lithium, sodium and potassium are all Group 1 elements.

A teacher adds a small piece of potassium to a trough of water, as shown in the diagram.

The potassium fizzes and a gas is produced.

Describe what else you would observe.

Reactivity increases going down Group 1 from lithium to potassium.

Explain this trend in reactivity.

Use ideas about the electronic configurations of the atoms in your answer.

Look at the table. It shows information about the Group 7 elements.

Complete the table.

Element	Formula	Colour	State at room temperature
Fluorine	F2	pale yellow	gas
Chlorine	C2	.........................	.........................
Bromine	Br2	brown	liquid
Iodine	I2	grey	.........................

The Group 7 elements exist as simple molecules.

Fluorine boils at −188°C.

Explain why fluorine has a low boiling point.

The elements in Group 0 (the noble gases) are unreactive.

Explain why, in terms of their electronic configurations.