The document discusses two types of bonding: covalent and ionic. Covalent bonding involves the sharing of electron pairs between non-metal atoms to form molecules. Ionic bonding occurs between a metal and non-metal where the metal transfers electrons to the non-metal to form oppositely charged ions in a giant lattice structure. This ionic lattice structure results in high melting and boiling points due to the strong electrostatic forces between the ions.

1. - Try to get stable configuration like noble gas ( full valence shell )
 Octet – 8 electrons ( first shell 2, 2 onwards 8 )
 Duplet – 2 electrons
- When proton not equal to electron -> ion
- Cation (positive) Anion (negative)
- Transfer of electrons
Covalent bonding
- Non-metals
- Electrons shared between non-metals
- “ – “ means one covalent bond 1 pair of electrons shared
- Mono, di, tri, tetra, penta , hexa
- Giant molecular structure
 Physical properties (why high melting point?)
 Chemical properties
- Simple molecular structure
 Physical properties (why low melting point?)
 Chemical properties
Ionic bonding
- Metal and non-metal
- Metallic atom give electron to non-metallic atom
- I, II, IV lose valence electrons
- V, VI, VII gain electrons
- Sometimes ion have two positive charge so FeCl2 = Iron (II) chloride
- Giant ionic lattice structure
 Physical properties (why high melting point?)
Giant ionic structure , oppositely charged ions held together in giant 3-D lattice
Sea of positive and negative ions
When water added to ionic compounds, ions become mobile and can conduct
electricity.
When compound is melted or in molten state, ions also become mobile.
High boiling and melting point, solid at room temperature as a lot of heat / energy is
needed to overcome strong electrostatic forces.
Soluble in water, not organic solvents.
 Chemical properties
Strong electrostatic forces of attraction between oppositely charged ions.
- Dot & cross diagram
 Only valence shell, no need inner circle.
 Must draw brackets; write charges, number of atom in front of bracket, symbol of
element.
 Use dot for one element, cross for another.
 Must write legend.
 Covalent – need to overlap