Question

Can please anyone explain me the first line .?How can there be p-p overlapping between Be Cl .

Answer 1

This is due to covalent bonding and not ionic-bonding.

Hope this helps 

Cheers

Answer 2

Hello friend !!!

Here's the answer you are looking for

During bond formation sometimes the constituent elements are excited.

Let's take example here BeCl2

The electronic configuration of

Be is 1s2 2s2

Due to no vacant orbital, it's comes to it's excited state to form bond and gain a stable electronic configuration

When it is excited, it's electronic configuration become 1s2 2s1 2p1

Hence it forming bond with Cl, one Cl is bonded with a orbital of Be and other p orbital

Thus one has hybridisation s-p and the other has p-p

★★ HOPE THAT HELPS ☺️ ★★