Chemical Changes | MCQs

Explanation

• Burning of wood is a chemical change, as it involves a chemical reaction between the wood and oxygen.
• Resulting in a change in chemical composition and the formation of new substances (ashes, carbon dioxide, water vapor, etc).

Explanation

• Melting of ice is a physical change, as it only involves a change in state (from solid to liquid) without a change in chemical composition.

The examples of chemical changes:

• Burning of fuel
• Explosion of firework
• Burning of wood
• Cooking of food (breakfast, lunch, dinner)
• Bursting of crackers
• Burning of wax
• Rusting of iron
• Heating sulphur with iron fillings (to produce iron sulphide)
• Digestion of food
• Respiration in living things
• Photosynthesis in plants

Explanation

• A chemical change, also known as a chemical reaction.
• It is a process that alters the composition of one or more substances, resulting in the formation of new substances with different properties.

Explanation

The correct answer is: No change in composition

• A chemical change involves a transformation of one or more substances into new substances, which means a change in composition.

The signs of chemical change:

• Release of gas
• Change in color
• Change in temperature
• Change in smell
• Production of a new material