Hydrogen Bonding
Hydrogen bonds occur between positive hydrogen atoms and negatively charged atoms.
The attractive forces between water molecules are due to hydrogen bonding. Hydrogen atoms in one water molecule are attracted to the negatively charged oxygen atoms of another water molecule.
Covalent Bonding
Covalent bonds occur when two or more atoms share electrons in order to become more stable. Non-metal elements form covalent bonds.
A water molecule has two covalent bonds where two hydrogen atoms share an electron with an oxygen atom.
Ionic Bonding
Ionic bonds occur when electrons are transferred from one atom to another in order for them both to become more stable.
Ionic bonds happen when a non-metal atom accepts an electron from a metal atom that loses an electron. The result of ionic bonding is two oppositely charged ions. An ion is an atom that has an electric charge.
Example:
Table salt is formed by the ionic bonding between sodium and chlorine. When Na (Sodium) donates an electron to a Cl (Chlorine) atom, the result is a positive Na+ ion, and a negative Cl- ion.