⚗️ Changes Around Us: Physical and Chemical
Science – Chapter 5 (Questions & Answers)
Q1. What is a physical change?
Answer: A physical change is a change in which no new substance is formed and it is usually reversible.
Q2. What is a chemical change?
Answer: A chemical change is a change in which a new substance is formed and it is usually irreversible.
Q3. Give examples of physical changes.
Answer: Melting of ice, boiling of water, and cutting paper.
Q4. Give examples of chemical changes.
Answer: Rusting of iron, burning of paper, and cooking food.
Q5. What are the characteristics of a chemical change?
Answer: Formation of a new substance, change in color, release of gas, and production of heat or light.
Q6. What is rusting?
Answer: Rusting is a chemical change in which iron reacts with oxygen and moisture to form rust.
Q7. What is reversible change?
Answer: A change that can be reversed to get the original substance back.
Q8. What is irreversible change?
Answer: A change that cannot be reversed to get the original substance back.
Q9. Why are chemical changes important?
Answer: They are useful in cooking, digestion, industry, and many daily life processes.