Question

Arrange the given metals in the order of increasing reactivity towards oxygen: $Mg,Cu,K,Na$

• A. $Cu<Mg<Na<K$
• B. $Cu<Mg<K<Na$
• C. $Mg<Cu<Na<K$
• D. $Cu<K<Na<Mg$

Answer 1

The correct option is A $Cu<Mg<Na<K$

$Cu<Mg<Na<K$ (based on reactivity series)

In the reactivity series, highly reactive elements are placed on the upper side and less reactive metals are placed on the lower side. $Cu$ does not react with oxygen at ordinary temperature and Mg is more reactive than $Cu$. $K$ is placed high in the series followed by $Na$ based on the reactivity.