Answer:
a) Physical change
b) Physical change
c) Chemical change
d) Physical change
e) Chemical change
f) Chemical change
Step-by-step explanation:
Physical Change:
Type of change in which no new substance is formed, only change in shape or physical state is occur. Physical change can be reversed by reversing the condition.
Chemical Change:
A type of change in which new substance is formed and the change occured cannot be reversed.
A) A piece of copper is hammered to a different shape. Physical change
In this change, only shape of copper is changed.
(b) Frost is formed when solid surfaces are cooled to below the dew point. Physical change
Here, water vapour are changed to ice, i.e. change in physical state.
(c) Microorganisms decompose nitrate from the soil to form nitrogen gas. Chemical change
In this change, a new substance is formed.
(d) As air temperature rises, its ability to hold water vapor increases significantly. Physical change
No new substance is formed.
(e) Nitrous oxide is produced by the combustion of gasoline in industrial processes. Chemical change
New substance, nitrous oxide is produced.
(f) With the help of sunlight, photosynthesis produces oxygen when carbon dioxide and water are chemically converted into glucose. Chemical change
New substances are formed in this change.