Correct the statement.

Formula of magnesium sulphide is ${\mathrm{Mg}}_2\mathrm{S}$.

Identify the physical and chemical change in the given example :

Preparation of liquefied petroleum gas

Identify the physical and chemical change in the given example :

Usage of liquefied petroleum gas

Identify the physical and chemical change in the given example :

Formation of manure

Identify the physical and chemical change in the given example :

Formation of glass

Identify the physical and chemical change in the given example :

Breaking of glass

Classify it into different changes:

Making of dough from flour.

Classify it into different changes:

Digestion of food.

Classify it into different changes:

Germination of seeds