Question

can anyone solve this as fast as possible please... 1. Condition necessary for rusting is __________. * -Presence of air. -Presence of water -Both a & b -None of these. 2. Apple turns brown in colour after cutting. It is an example of ___________ . -Physical change -Chemical change -No change -Reversible change 3. The process of depositing a layer of zinc over another metal surface to protect it from rusting is called ______________. -Galvanisation -Crystallaisation -Neutralisation -Combination 4. Which of the following metals undergo rusting? -Zinc -Iron -Aluminum -Gold 5. Alloy that is made by mixing iron with Carbon, Nickel, Manganese is called ____________. -Stainless steel -German Silver -Nichrome -Aluminum 6. Physical changes are ________________. -Reversible -Irreversible -Permanent -All of the above 7. Turning milk into curd is a _____________. -Physical change -Temporary change -Chemical change -None of the above 8. A chemical change may involve ___________. -Change in color -Change in temperature -Evolution of gas -All of the above 9. Which of the following is a chemical change? -Boiling of water -Tearing of newspaper -Boiling of egg -Freezing water into ice 10. When ice is heated, it changes to water and water on further heating gets converted to steam. What happens when steam is condensed? -A new substance is formed -No new substance is formed -Gaseous state changes into liquid state -Both b and c are correct CLASS 7

Answer 1

Answer:

1)both a and b

2) chemical change

3)galvanisation

4)iron

5) stainless steel

6)all of the above

7) chemical change

8)all of the above

9) boiling of egg

10)both b and c are correct

Answer 2

Answer:

Explanation:

1:both a&b

2:chemical change

3:galvanisation

4:zinc

5:stainless steel