CBSE Class 10 Answered

Limitiations of octet rule:

1.  It was based on chemical inertness of noble gases.But some nobel gases like Xenon combines with oxygen and fluorine to form compounds.

2. It does not predict the shapes of compounds.

3. Some compounds like BCl₃, BeH₂ have incomplete octet of the central atoms B and Be.

4. Some molecules are odd electron molecules like NO and NO₂

5. In some molecules, ceontral atom has more than 8 electrons like SF₆, PCl₅.

Factors affeacting ionic bonding:

An ionic bond is formed when one of the atoms have a tendency to lose electrons that is it has 1,2, or 3 electrons in the valence shell and the other atom has a tendency to accept electrons that is it has 5,6,or 7 electrons in the valence shell. The ionic bond is formed by the transfer of electrons from the atom which can donate electrons to the atom whic has the tendency to accept electrons.