PDF CHEM1001 Worksheet 3: Ionic and Covalent Bonding Model 2: Covalent bonding The interaction between two non-metals is covalent. Two (or more) non-metals form covalent bonds. In a covalent bond, two atoms share their electrons, in order for each to gain a noble gas configuration. For most of the atoms you come across, this will mean having 8 electrons in the valence shell - the octet rule.