(exam) physical and chemical change

Question 1

3 characteristics of a chemical change

Answer 1

1. A new substance forms
2. Usually hard to reverse
3. Bonds break or form

Question 1

3 characteristics of a physical change

Answer 1

1.No new substance formed
2. Often easily reversible
3. Bonds don’t change

Question 2

Physical change =

Answer 2

When the appearance of a substance is changed, but the chemical makeup remains the same

Question 3

4 indicators of physical change

Answer 3

1. Change in shape or form
2. mixing
3. expansion (heat is added) / contraction (heat is removed)
4. change of state

Question 4

4 indicators of a chemical change

Answer 4

gas production
colour change
formation of precipitate
energy production or absorption

Question 5

What is a chemical change

Answer 5

A change that causes a new substance to be formed

Question 6

Precipitate formation

Answer 6

When two aqueous solutions are mixed and an insoluble solid product is formed, that is precipitate formation

Question 7

What happens to bonds during chemical changes

Answer 7

During a chemical change some of the chemical bonds between atoms are broken and new bonds form

Question 8

Law of conservation of mass

Answer 8

Matter cannot be destroyed or created, particles only rearrange. (Total mass of all reactants will be equal to the total mass of all products)