Question

Covalent hydrides among $Ca{H}_2,N{H}_3,NaHand{B}_2{H}_6$ are _____

• A. NH₃ and B₂H₆
• B. NaH and CaH₂
• C. NaH and NH₃
• D. CaH₂ and B₂H₆

Answer 1

The correct option is A

NH₃ and B₂H₆

For covalent hydrides, H should bond with elements of electronegativity close to it.
$N{H}_3$ is a covalent compound.
Na and Ca are highly electropositive.
Thus, $B_2{H}_6$ is also a covalent compound
(Remember that B is left of C which forms covalent bonds with H)