Material changes

Question 1

What is the difference between chemical reaction and physical change ?

Answer 1

Chemical reaction : It forms a new substance and cannot be reversed back

Physical change : It changes physical matters but it is réversible

Question 2

What is another word for burning ?

Answer 2

Combustion

Question 3

How do we test for the presence of carbon dioxide ?

Answer 3

Use limewater

And if carbon dioxide is present the water will become foggy and milky

Question 4

What causes rusting or a metal ?

Answer 4

Water and oxygen

Question 5

What happens when something burns ?

Answer 5

Reacts with oxygen in the air and sometimes form ashes called hydroxide

Question 6

Is rusting a chemical reaction or physical change ?

Answer 6

Chemical reaction

Question 7

How do we prevent rusting a metal ?

Answer 7

Paint it