Question

$Ca{{H}_{2}}$ is an example of :
A. Ionic hydride
B. Covalent hydride
C. Metallic hydride
D. Polymeric hydride

Answer 1

Hint: The covalent compounds are going to form by sharing the electrons between the atoms involved in the chemical reaction. At the same time ionic compounds are going to form by donating and accepting the electrons between the atoms.

Complete Solution :
- In the question it is asked that calcium hydride belongs to which category among the given options.
- To know about the nature of calcium hydride we should know the electronic configuration of the calcium and hydrogen.
- The electronic configuration of calcium is $1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}4{{s}^{2}}$ .
- To get the octet electronic configuration of calcium, calcium loses two electrons. After losing the two electrons calcium will get inert electronic configuration.
- Then calcium loses electrons and those two electrons are accepted by the hydrogens.
- Then the compound calcium hydride is going to form by the donation of electrons by the calcium and those electrons are accepted by the two hydrogen atoms.
- Therefore the calcium hydride is an ionic compound or ionic hydride.
So, the correct answer is “Option A”.

Note: In ionic compounds the electrons are accepted by the high electronegative atom and the electrons are donated by the metals or the atoms which have less electronegative atoms. The covalent bond is formed between the atoms having the same electronegativity values. The formation of ionic or compound is going to depend on the electronegativities of the atoms involved in the bonding.