science chemical reactions

Question 1

Give 2 characteristics and 1 example of a chemical reaction.​
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Answer 1

New substance is formed/it is irreversible- e.g. cooking​

Question 2

Give 2 characteristics and 1 example of a physical reaction.​

Answer 2

It is reversible/no new substance is formed- e.g. freezing water​

Question 3

What is the name of the process in which a solid turns into a gas?​

Answer 3

Sublimation ​

Question 4

What is the name of the process in which ice turns into water?​

Answer 4

Melting​

Question 5

What does copper carbonate look like before and after heating?

Answer 5

Before-green solid. After – Black solid​

Question 6

What is the new substance formed when magnesium is heated?​

Answer 6

Magnesium Oxide​

Question 7

Is heating iodine a chemical or physical change?​

Answer 7

Physical ​

Question 8

Name three things needed to keep a fire burning.​

Answer 8

Heat, oxygen and fuel​

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