Ionic Bonding
The electrostatic attraction between positively charged ions (cations) and negatively charged ions (anions).
Key Points on Ionic Bonding
Formed when metals lose electrons (cations) and non-metals gain electrons (anions).
Example: Sodium (Na) loses one electron to become Na⁺; Chlorine (Cl) gains one electron to become Cl⁻.
Properties: High melting and boiling points, conduct electricity when molten or dissolved in water.
Covalent Bonding
A bond formed by the sharing of pairs of electrons between atoms.
Key Points on Covalent Bonding
Each shared pair of electrons constitutes one covalent bond.
Example: In water (H₂O), oxygen shares electrons with two hydrogen atoms.
Properties: Lower melting and boiling points compared to ionic compounds; do not conduct electricity.
Metallic Bonding
The electrostatic attraction between positively charged metal ions and a sea of delocalised electrons.
Key Points on Metallic Bonding
Metals are good conductors of electricity and heat due to the movement of delocalised electrons.
Properties: Malleable and ductile; high melting and boiling points.