What do you understand by (i) Electron-deficient (ii) Electron-precise (iii) Electron-rich compounds of hydrogen? Provide justification with suitable examples.

Explanation

(1) Electron deficient hydrides: Compounds in which central atom has incomplete octet, are called electron deficient hydrides. For example, `BeH_(2)`, `BH_(3)`, are electron deficient hydrides.
(ii) Electron precise hydrides: Those compounds in which exact number of electrons are present in central atom or the central atom contains complete octet are called precise hydrides e.g., `CH_(4)`, `SiH_(4)`, `GeH_(4)`, etc. are precise hydrides.
(iii) Electron rich hydrides: Those compounds in which central atom has one or more lone pair of excess electrons are called electron rich hydrides. e.g., `NH_(3)`, `H_(2)O`.