MEDIUM
7th CBSE
IMPORTANT
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The iron compound that forms due to the reaction of iron with water and oxygen is known as

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Important Questions on Changes of Matter

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.
MEDIUM
7th CBSE
IMPORTANT
Copper is more reactive than iron.
EASY
7th CBSE
IMPORTANT
A physical change can be reversed.
EASY
7th CBSE
IMPORTANT
With a chemical change, no new substance is formed.
MEDIUM
7th CBSE
IMPORTANT

Complete the analogies:

Acetic acid : vinegar : :_____: sodium hydrogen carbonate