NCERT Solutions for Class 7 Science Chapter 6: Physical and Chemical Changes

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NCERT Solutions for Class 7 Science Chapter 6 Physical and Chemical Changes are provided in the article below. The important topics covered in this chapter are:

Physical changes
Chemical changes
Rusting of iron
Crystallization

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NCERT Solutions for Class 7 Science Chapter 6

NCERT Solutions for Class 7 Science Chapter 6 Physical and Chemical Changes are given below:

Class 7 Science Chapter 6 Physical and Chemical Changes: Important Topics

A Physical change is a temporary change that affects only physical properties such as shape, and size. It is said that, whenever a substance goes through a physical change, its composition remains the as it is despite its molecules being rearranged. A chemical change is a permanent change having both physical and chemical properties of a substance. It is said that whenever a substance goes through a chemical change, its molecular composition is completely changed.

Physical changes

Physical changes are defined as the changes affecting the form of a chemical substance, but not it is chemical composition. Physical changes are generally used to separate mixtures into their component compounds, but can not be used to separate compounds into chemical elements or simpler compounds.

Chemical changes

Chemical changes take place when a substance combines with another in order to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. These processes are known as chemical reactions which, in general, are not reversible except by further chemical reactions.

Rusting of iron

Rusting of iron is an oxidation reaction. The iron reacts with water and oxygen in order to form hydrated iron(III) oxide, which we perceive as rust. Iron and steel rust when they come into contact with water and oxygen – both are needed for rusting to occur.

Chapter Related Links:

Difference Between Physical and Chemical Changes	Chemical change	Difference between physical and chemical properties
Oxygen Cycle	Examples of Weak Acids	Noble Gases
Weak Base	Difference Between Acid and Base	Solvent Examples

Class 7 Science Additional Resources:

CBSE Class 7 Science NCERT Textbook	CBSE Class 7 Science Sample Paper	NCERT Solutions

CBSE X Related Questions

1.
The natural sources of oxalic acid, lactic acid and methanoic acid respectively are:

tomato, curd, ant-sting
tomato, orange, nettle-sting
orange, milk, ant-sting
orange, sour milk, nettle-sting

View Solution

2.
Which of the following group is not 'biodegradable'?

Vegetable peels, dead leaves, paper
Cow dung, leather bag, water
Polythene bag, rubber band, ball pen
Paper, fruits, bones

View Solution

3.
The reasons for excessive generation of wastes are:
(i) Use and throw policy.
(ii) Increased availability of packaged food.
(iii) Increased construction wastes.
(iv) Non-sorting of dry and wet wastes

(i), (iii) and (iv)
(i), (ii) and (iii)
(i), (ii), (iii) and (iv)
(ii), (iii) and (iv)

View Solution

4.
Identify the correct statement for spirogyra, leishmania and hydra

they reproduce sexually.
they are unicellular.
they are multicellular.
they reproduce asexually.

View Solution

5.
Assertion : Reaction of quick lime with water is an exothermic reaction. Reason (R): A large amount of heat is evolved on the reaction of quick lime and water.

Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
Assertion (A) is true, but Reason (R) is false.
Assertion (A) is false, but Reason (R) is true.

View Solution

6.
Sex is determined by different factors in various species. However, in human beings, it is determined genetically. Which amongst the following option(s) is/are correct for human beings ?
Gamete carrying X chromosome from female parent.
Gamete carrying X chromosome from male parent.
Gamete carrying Y chromosome from male parent.

(ii) and (iii)
(i) only
(i) and (iii)
(iii) only

View Solution

NCERT Solutions for Class 7 Science Chapter 6: Physical and Chemical Changes

NCERT Solutions for Class 7 Science Chapter 6

Class 7 Science Chapter 6 Physical and Chemical Changes: Important Topics

Physical changes

Chemical changes

Rusting of iron

CBSE X Related Questions

1.
The natural sources of oxalic acid, lactic acid and methanoic acid respectively are:

2.
Which of the following group is not 'biodegradable'?

3.
The reasons for excessive generation of wastes are:
(i) Use and throw policy.
(ii) Increased availability of packaged food.
(iii) Increased construction wastes.
(iv) Non-sorting of dry and wet wastes

4.
Identify the correct statement for spirogyra, leishmania and hydra

5.
Assertion : Reaction of quick lime with water is an exothermic reaction. Reason (R): A large amount of heat is evolved on the reaction of quick lime and water.

Similar Science Concepts

Comments

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NCERT Solutions for Class 7 Science Chapter 6: Physical and Chemical Changes

NCERT Solutions for Class 7 Science Chapter 6

Class 7 Science Chapter 6 Physical and Chemical Changes: Important Topics

Physical changes

Chemical changes

Rusting of iron

CBSE X Related Questions

1.The natural sources of oxalic acid, lactic acid and methanoic acid respectively are:

2.Which of the following group is not 'biodegradable'?

3.The reasons for excessive generation of wastes are: (i) Use and throw policy. (ii) Increased availability of packaged food. (iii) Increased construction wastes. (iv) Non-sorting of dry and wet wastes

4.Identify the correct statement for spirogyra, leishmania and hydra

5.Assertion : Reaction of quick lime with water is an exothermic reaction. Reason (R): A large amount of heat is evolved on the reaction of quick lime and water.

Similar Science Concepts

Comments

SUBSCRIBE TO OUR NEWS LETTER

1.
The natural sources of oxalic acid, lactic acid and methanoic acid respectively are:

2.
Which of the following group is not 'biodegradable'?

3.
The reasons for excessive generation of wastes are:
(i) Use and throw policy.
(ii) Increased availability of packaged food.
(iii) Increased construction wastes.
(iv) Non-sorting of dry and wet wastes

4.
Identify the correct statement for spirogyra, leishmania and hydra

5.
Assertion : Reaction of quick lime with water is an exothermic reaction. Reason (R): A large amount of heat is evolved on the reaction of quick lime and water.