Question

Which of the following alkali metal did not easily tarnish in air?

• A. $Be$
• B. $Ca$
• C. $Mg$
• D. $Sr$

Answer 1

The correct option is A $Be$

Option $\left(A\right)$ is correct.

$Be$ does not easily tarnish in the air because the surface of beryllium metal is covered with a thin layer of oxide that helps protect the metal from attack by air. It does not oxidize in the air even at 600${}^{\circ }C$.