1) Physical change. This type of change affects the form of a substance, but the chemical composition is not changed. Examples: magnetism, solution, melting
Chemical change. This type of change affects the chemical composition of the substance. Examples: combustion, production of odor after mixing two compounds.
The dissolution of table salt in water. This is a physical change. Only the state changes.
The dissolution of zinc in tetraoxo sulphate (vi) acid.
The melting of the candle. The melting of wax is a physical change and the burning of the wick is a chemical change.
Sublimation of iodine. This is a physical change since it is the conversion from one state (solid) to another one (gaseous).