The oxide of element X is reduced by heating with carbon. Element X does not react with cold water, steam or dilute hydrochloric acid. What is X?

The question is incomplete, the complete question is;

The oxide of element X is reduced by heating with carbon.

Element X does not react with cold water, steam or dilute hydrochloric acid.

What is X?

A copper

B iron

C magnesium

D zinc

Answer:

Copper

Explanation:

Copper is below hydrogen in the activity series of metals. Remember that the activity series of metals is an arrangement of metals in order of decreasing reactivity from most reactive to least reactive. The metals at the head of the series are highly reactive, metals at the middle of the series are moderately reactive while metals below hydrogen in the series are least reactive.

Copper being below hydrogen in the series cannot displace it from water (cold or steam) or from dilute acid solutions. Copper can be reduced by heating it with carbon (thermal reduction).