Consider this reaction: Mg(s) + 2H20(1) ► Mg(OH)2(s) + H2(9)

What is the oxidation state of Mg in Mg(s)?

Oxidation state for Mg(s) is 0

Explanation:

This is redox reaction, where one element is oxidized and another is reduced.

H from water is being reduced while the Mg which is in ground state is oxidized.

When the element is reduced, the oxidation state is decreased:

2H⁺ + 2e⁻  ⇄  H₂

When the element is oxidized, the oxidation state is increased

Mg ⇄ Mg²⁺ + 2e⁻

As Mg(s) in the product side, is at ground state, the oxidation state is 0.

Any element in ground state has 0, as oxidation state.

where are the choice options?

it is the most commonly accepted one