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
The chemical name of Baking soda is
  • A
    Sodium carbonate
  • B
    Calcium carbonate
  • C
    Calcium hydrogen carbonate
  • D
    Sodium hydrogen carbonate
    Correct
2
The changes in which only _______________ properties are changed are called physical changes.
  • A
    Structural
  • B
    Natural
  • C
    Chemical
  • D
    Physical
    Correct
3
Which is an example of both physical as well as chemical changes?
  • A
    Melting of wax
  • B
    Burning of candle
    Correct
  • C
    Respiration
  • D
    Digestion
4
Painting of iron articles prevent the rusting because
  • A
    Paint is a reducing agent
  • B
    Air and water do not come in contact of surface
    Correct
  • C
    Paint change oxygen into carbon dioxide
  • D
    Paint absorbs the moisture
5
Magnesium ribbon burns with
  • A
    Dull white light
  • B
    Black fume
  • C
    Brilliant white light
    Correct
  • D
    Red bright light
6
The gas we use in kitchen is called LPG, which stands for
  • A
    Liquefied purified gas
  • B
    Liquefied petroleum gas
    Correct
  • C
    Liquid petrol gas
  • D
    Liquefied permanent gas
7
Anaerobic bacteria, digest animal waste and produce
  • A
    Sulpher dioxide gas
  • B
    Producer gas
  • C
    Hydrogen gas
  • D
    Bio gas
    Correct
8
LPG gas is liquefied by applying
  • A
    Low pressure and low temperature
  • B
    Low pressure and low temperature
  • C
    High pressure and low temperature
    Correct
  • D
    High pressure and high temperature
9
Melting of ice is a
  • A
    Chemical change
  • B
    Periodic change
  • C
    Physical change
    Correct
  • D
    Both physical and chemical change
10
Which of the following is an example of physical change?
  • A
    Boiling of water
    Correct
  • B
    Rusting of iron
  • C
    Ripening of fruit
  • D
    A bud turning into flower
11
Which of the following statement is true for a physical change?
  • A
    It change a substance into different substance
  • B
    More than one substance must be present
  • C
    Burning is an example
  • D
    It alter the form and appearance of the substance
    Correct
12
Pinki added a spoon of salt in a glass of water and stirred it, the salt disappear. Which type of change is this?
  • A
    Chemical change
  • B
    No any change
  • C
    Physical change
    Correct
  • D
    Biological change
13
\({\text{Mg }} + {\text{ }}{{\text{O}}_{{\text{2 }}}} \to ?\)
  • A
    \({\text{M}}{{\text{g}}_{\text{2}}}{\text{O}}\)
  • B
    \({\text{Mg}}{\left( {{\text{OH}}} \right)_{\text{2}}}\)
  • C
    \({\text{Mg}}{{\text{O}}_{\text{2}}}\)
  • D
    MgO
    Correct
14
Magnesium ribbon burns with
  • A
    Red bright light
  • B
    Dull white light
  • C
    Black fume
  • D
    Brilliant white light
    Correct
15
Which of the following may not be followed by a chemical reaction?
  • A
    Change in temperature
  • B
    Change in smell
  • C
    Change in physical state and size
    Correct
  • D
    Change in colour