Classify the following as physical and chemical changes: Photosynthesis in plants.

Photosynthesis is a chemical process which is conducted in plants in the presence of chlorophyll. In this process plants take in water and carbon dioxide to prepare carbohydrate as their food and energy resource.

Classify the following as physical and chemical changes: Burning of kerosene oil in a stove.

Burning is a combustion process in which a fuel reacts with atmospheric oxygen to give heat and light energy to the surrounding. It is an exothermic process. Since, during combustion, the chemical composition of kerosene is changed to give carbon dioxide and water vapours, therefore, it is a chemical change.

Classify the following as physical and chemical changes: Beating gold into thin foil.

Gold is a malleable and ductile metal. It can easily be beaten to change its shape into thin foils. Since, in this process only the shape of the metal is changed therefore, it is a physical change.

Classify the following into acids, bases and salts: NaCl

NaCl is known as sodium chloride which is a salt also known as common salt. It is formed by the neutralisation reaction between a base sodium hydroxide and hydrochloric acid.

Classify the following into acids, bases and salts: NaHCO 3

NaHCO 3 is sodium bicarbonate which is a salt made by the neutralisation reaction between sodium hydroxide and carbonic acid.

Classify the following into acids, bases and salts: H 2 SO 4

H 2 SO 4 is an acid that can turn blue litmus red. It is a mineral acid that is strong in nature which means that is completely ionises in the solution. It is corrosive in nature. It is also known as oil of vitriol.