Covalent Bonding

• When atoms share pairs of electrons, they form covalent bonds. These bonds between atoms are very strong
• Covalently bonded substances may consist of small molecules
• Atoms only share electrons in the outer shell, each single covalent bond provides one extra shared electron for each atom
• Some covalently bonded substances have very large molecules, such as polymers
• Some covalently bonded substances have giant covalent structures, such as diamond and silicon dioxide