Covalent compounds are formed when

a metal bonds with a metal
a nonmetal bonds with a nonmetal
a metal bonds with a nonmetal
a metal bonds with a noble gas

Respuesta :

a nonmetal bonds with a nonmetal, eg. Carbon and Oxygen form CO2 or CO

Metals and nonmetals form ionic bonds, metals don't bond with each other, and most noble gases don't bond at all.

Hope this helps! :)