What are the favourable conditions for covalent bond formation?

What are favourable conditions for the formation of anion?

Favourable conditions for physical adsorption are

Favourable conditions for physical adsorption are

The favourable conditions for a spontaneous reaction are

O_(3) is prepared by subjecting 0, to silent electric discharge. The favourable conditions for the formation of ozone according to Le-chatlier's principle are

In the formation of covalent bond

Covalent bond exists in