Material changes Flashcards
1
Q
What is the difference between chemical reaction and physical change ?
A
Chemical reaction : It forms a new substance and cannot be reversed back
Physical change : It changes physical matters but it is réversible
2
Q
What is another word for burning ?
A
Combustion
3
Q
How do we test for the presence of carbon dioxide ?
A
Use limewater
And if carbon dioxide is present the water will become foggy and milky
4
Q
What causes rusting or a metal ?
A
Water and oxygen
5
Q
What happens when something burns ?
A
Reacts with oxygen in the air and sometimes form ashes called hydroxide
6
Q
Is rusting a chemical reaction or physical change ?
A
Chemical reaction
7
Q
How do we prevent rusting a metal ?
A
Paint it
