Question

Which of these statements gives the correct picture regarding halogens and alkali metals with respect to an increase in the atomic number?

Options

• Reactivity decreases in alkali metals but increases in halogens.

• Reactivity increases in both.

• Reactivity decreases in both.

• Reactivity increases in alkali metals but decreases in halogens.

Answer 1

Reactivity increases in alkali metals but decreases in halogens.

Explanation:

Down group 1, alkali metals lose their outer electron more readily, so their reactivity increases. Down group 17, halogens become less able to gain an electron, so their reactivity decreases.