Chemical Changes

Which of the following is a chemical change?

• evaporation of a puddle of water

• photosynthesis

• formation of ice cubes in the freezer

• melting of ice glaciers

Which of the following is a physical change?

• burning of candle

• crushing a can

• mixing vinegar with baking soda

• ripening fruits

Chemical change can be both useful and harmful.

• True

• False

Which of the following chemical changes is NOT a useful change?

• cooking

• respiration

• photosynthesis

• rusting

Examples of chemical changes include interactions between matter and heat, matter and light, matter and electricity and mixing of different matter.

• True

• False

When matter interacts with oxygen, which of the following chemical changes occur? Select all the possible changes.

• combustion

• neutralisation

• photosynthesis

• respiration

• rusting

When matter interacts with light, which of the following chemical changes occur? Select all the possible changes.

• combustion

• electroplating

• electrolysis

• image formed on an X-ray film

• photosynthesis

What is the name of the reaction between an acid and alkali?

What is the name of the chemical change for producing glucose and oxygen by green leaves in the presence of sunlight?

What is the name of the reaction for heating and breaking down mercury oxide into mercury and oxygen?