MEDIUM
7th CBSE
IMPORTANT
Earn 100

The necessary condition for rusting is

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Important Questions on Changes of Matter

MEDIUM
7th CBSE
IMPORTANT
Which of these is not a method for preventing rusting in metals?
EASY
7th CBSE
IMPORTANT
Combustion takes place in the presence of
MEDIUM
7th CBSE
IMPORTANT
The activity which shows both physical and chemical changes is
MEDIUM
7th CBSE
IMPORTANT
The iron compound that forms due to the reaction of iron with water and oxygen is known as
MEDIUM
7th CBSE
IMPORTANT
_____ is an alloy of iron and carbon.
MEDIUM
7th CBSE
IMPORTANT

Match the following to show changes. Identify each as a physical or chemical change.

Column A Column B
a)decomposition of i)a magnesium ribbon
b)cutting a ii)old leaves
c)blowing of iii)rubber band
d)stretching of a iv)balloons
e)souring of v)copper wire
f)burning of vi)milk

 

EASY
7th CBSE
IMPORTANT
Tearing of paper is a physical change.
MEDIUM
7th CBSE
IMPORTANT
The presence of oxygen and water is necessary for rusting of iron.