関連ワード:  3 examples of covalent compounds    3 examples of covalent compounds and their uses    3 types of covalent compounds    3 examples of covalent bonds    3 types of covalent bonds    3 types of covalent bonds in chemistry    3 types of covalent bonds pdf    3 types of covalent bonds class 9    3 types of covalent bonds class 11    3 common properties of covalent compounds