Q1. Fill in the blanks.
i. Cutting a log of wood into pieces is a ____________ change.
ii. Condensation is a __________ change.
iii. When carbon dioxide is passed through lime water, it turns milky due to the formation of _____________________.
iv. Two methods by which rusting of iron can be prevented are __________________ and_____________________.
v. Changes in which only ____________properties of a substance change are called physical changes.
vi. A medicine is the end product of a chain of __________________.
i. Formation of manure from leaves is a physical change. ______
ii. Iron pipes coated with zinc do not get rusted easily. _______
iii. Iron and rust are the same substances. _______
iv. The chemical name of baking soda is Sodium hydrogencarbonate. ___
v. Changes in which new substances are formed are called chemical changes. _______
Q3. What type of change is crystallisation?
Q4. What type of change is involved in rusting of iron?
Q5. Write one property of stainless steel.
Q6. What type of change is formation of manure?
Q7. Which of the two is permanent change chemical change or physical change?
Q8. What do you understand by chemical change?
Q9. State the conditions necessary for rusting of iron?
Q10. What is galvanisation?
Q11. What is added to steel to make it stainless?
Q12. Why formation of manure from leaves is a chemical change?
Q13. Why souring of milk is a chemical change?
Q14. What is rust?
Q15. What is blue vitriol?
Q16. Name the two methods by which rusting of iron can be prevented.
Q17. What happens when baking soda is treated with vinegar?
Q18. Which technique is better for obtaining sugar from sugar solution?