What is a covalent bond? how can you tell how many covalent bonds an atom can make?

A covalent or molecular bond is the sharing of electrons between atoms. You can tell how many covalent bonds an atom can make by the number of electrons it has available to share along with using the octet rule which helps determine the number electrons that atoms can have in their outer most orbital, the maximum of eight, hence octet rule, from 1, 2, 3, or up to a maximum of r covalent bonds.