NEET2018ChemistryChemical Bonding and Molecular StructureActual
Among CaH 2 ,   BeH 2 ,   BaH 2 , what is the order of ionic character?
Options
- ABeH 2 < BaH 2 < CaH 2
- BCaH 2 < BeH 2 < BaH 2
- CBeH 2 < CaH 2 < BaH 2
- DBaH 2 < BeH 2 < CaH 2
Correct answer
C. BeH 2 < CaH 2 < BaH 2
Step-by-step solution
BeH 2 < CaH 2 < BaH 2 The size of the elements follow the order: Be < Ca < Ba Smaller the size of cation, more will be its polarizing power. Thus, a higher polarization will lead to a greater covalent character, or the least ionic character. Hence, BeH 2 will be least ionic. Top to bottom size of cation increase so covalent character decrease and ionic character increases.