Among `CaH_(2),BeH_(2),BaH_(2),` the order of ionic character is

Options

A. `BeH_(2) lt BaH_(2) lt CaH_(2)`
B. `CaH_(2) lt BeH_(2) lt BaH_(2)`
C. `BeH_(2) lt CaH_(2) lt BaH_(2)`
D. `BaH_(2) lt BeH_(2) le CaH_(2)`

Answer

C

Explanation

Key Concept The covalent character in an ionic bond can be decided by Fajan's rule.
According to this rule, compounds with small cation, large anion, more charge on cation or anion shows more covalent character. As the above conditions opposes, it shows ionic character. Since, the size of cation decreases in the order
`Ba^(2+) gt Ca^(2+) gt Be^(2+)`
Therefore, the correct order of ionic character will be
`BeH_(2) lt CaH_(2) lt BaH_(2)`.