What is meant by bond pair of electrons ?

What is meant by 'shielding of electrons’ in an atom?

Total number of lone pairs and bond pairs of electrons present in XeF_4 is

What is meant by drift velocity of electrons ?

In which case the sigma bond pair and pi bond pair of electrons both are attracted in the same direction (towards same atom):

What is meant by an ionic bond ?

What do you understand by bond pair electrons and lone pair electron