Class 7 Physical And Chemical Changes CBSE Questions & Answers

Class 7 · Physical And Chemical Changes

This is Science Class 7 Physical and Chemical Changes CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
When carbon dioxide gas is passed through lime water, the lime water turns
  • A
    Hydrogen gas is evolved
  • B
    Form precipitate
  • C
    Remain colourless
  • D
    Milky
    Correct
2
Which of the following is an example of physical change?
  • A
    Burning
  • B
    Melting
    Correct
  • C
    Corroding
  • D
    Rusting
3
When water freezes it undergoes a
  • A
    Physical change
    Correct
  • B
    Vaporisation
  • C
    Chemical change
  • D
    Sublimation
4
The compound formed, when carbon dioxide gas is passed through lime water is
  • A
    Calcium oxide and water
  • B
    Calcium oxide and water
  • C
    Copper carbonate and hydrogen gas
  • D
    Calcium carbonate and water
    Correct
5
Burning of coal, wood or leaves is a
  • A
    Physical change
  • B
    Temporary change
  • C
    Chemical change
    Correct
  • D
    Both physical and chemical change
6
When food get spoiled, it produce foul smell this is a
  • A
    Desirable change
  • B
    Chemical change
    Correct
  • C
    Periodic change
  • D
    Physical change
7
In chemical change ______________ takes place.
  • A
    Evolution of gas, change in colour or change in shape
  • B
    Change in state, change in colour or change in shape
  • C
    Temporary change in colour or change in temperature
  • D
    Evolution of gas, change in colour or change in temperature
    Correct
8
Which of the following is an example of physical change?
  • A
    Rusting
  • B
    Melting
    Correct
  • C
    Corroding
  • D
    Burning
9
For rusting presence of _______________ is essential.
  • A
    Air and carbon dioxide
  • B
    Air and water
    Correct
  • C
    Low temperature and humidity
  • D
    Water and humidity
10
When water freezes it undergoes a
  • A
    Vaporisation
  • B
    Sublimation
  • C
    Physical change
    Correct
  • D
    Chemical change
11
Which of the following method is used to prevent rusting?
  • A
    Painting and oiling
    Correct
  • B
    Acidifying and scrapping
  • C
    All of the above
  • D
    Washing and cleaning
12
The process of depositing a thin layer of zinc over iron to prevent it from rusting is called as
  • A
    Galvanisation
    Correct
  • B
    Chrome plating
  • C
    Polishing
  • D
    Anodising
13
Souring of milk is a
  • A
    Undesirable change
    Correct
  • B
    Periodic change
  • C
    Desirable change
  • D
    Physical change
14
In a chemical change
  • A
    Energy is always absorbed
  • B
    Energy is either absorbed or given out
    Correct
  • C
    Energy is given out
  • D
    Energy change do not occur
15
Photosynthesis is carried out by green plants, it is a
  • A
    Chemical change
    Correct
  • B
    Undesirable change
  • C
    Physical change
  • D
    Temporary change