1. Electron deficient hydrides are referred to those hydrides which contains deficit of electrons after the hydrogen bonding has been formed that is the octet is partially filled after the bond formation.2. Examples of such hydrides include the hydrides of Group 13 elements.3. These hydrides cannot be represented by simple Lewis structures and also they have tendency to accept electrons.

4. Since these hydrides have a tendency to accept electrons. Hence, they act as Lewis acids.