Tag: change around us

Questions Related to change around us

Example of the physical change is :
chemistry change around us physical changes changes and their classification physical changes

  1. respiration (inhaling oxygen gas and exhaling carbon dioxide gas)

  2. mixing vinegar and baking soda

  3. evaporating water

  4. burning fuel in your car

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Correct Option: C
Explanation:

In evaporation of water, only the physical state of water changes from liquid to gas, but not the chemical composition of water.

Hence the correct answer is option C.

When salt is dissolved in a glass of water, how many new substances are formed?

chemistry change around us physical changes changes and their classification physical changes

  1. $1$

  2. $2$

  3. $3$

  4. None

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Correct Option: B

Which of the following is a physical change?

chemistry change around us physical changes changes and their classification physical changes

  1. Magnetisation of iron

  2. Curdling of milk

  3. Burning of a candle

  4. Cooking of food

Show answer
Correct Option: A
Explanation:

Magnetization of iron is a physical change and not a chemical change as there is no change of state, no change of temperature, no smell and no evolution of gas. It is because: - No Chemical process is involved. - After demagnetizing the iron it will lose its magnetic power.

Which of the following is not a physical change?

chemistry change around us physical changes changes and their classification physical changes

  1. Tearing a paper

  2. Bending an iron rod

  3. Freezing water into ice

  4. Curdling of milk

Show answer
Correct Option: D
Explanation:

Tearing of paper is a physical change because it remains same. Tearing of a paper is a physical change because when the paper is torn only the appearance of the paper is changed and no new substance is formed.

Cheese is made when an enzyme called rennet is added to milk. The rennet causes a chemical reaction where the milk solids curdle, separating themselves from the whey, or liquid portion of the milk

When a substance has changes in its physical properties than it is known as:

chemistry change around us physical changes changes and their classification physical changes

  1. Structural change

  2. Biological change

  3. Physical change

  4. Chemical change

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Correct Option: C
Explanation:

Change in only physical properties is known as physical change.

Which one of the following is a reversible change?

chemistry change around us physical changes changes and their classification physical changes

  1. cutting wood in pieces

  2. blooming of flowers

  3. melting of ice

  4. the burning of a candle

Show answer
Correct Option: C
Explanation:

Melting of ice is a physical change in which substance changes its physical state but not properties.


 Hence it is a reversible change in which melted ice can freeze again by decrease in temperature.

Hence the option C is correct.

Properties such as shape, size, colour and state of a substance are called it's:

chemistry change around us physical changes changes and their classification physical changes

  1. chemical properties

  2. physical properties

  3. chemical changes

  4. none of these

Show answer
Correct Option: B
Explanation:

Properties such as shape, size, colour and state of a substance are called its physical properties.A physical change is generally reversible. In such a change no new substance is formed.

Which of the following is a physical change?

chemistry change around us physical changes changes and their classification physical changes

  1. Rusting of Iron.

  2. The burning of coal

  3. Cooking food

  4. Converting ice in the water

Show answer
Correct Option: D
Explanation:

Change in the state between solid, liquid and gas is a physical change because Properties such as shape, size, colour and state of a substance are called its physical properties which are reversible.


Hence the option D is correct.

The process of obtaining salt by the evaporation of sea water is a :

chemistry change around us physical changes changes and their classification physical changes

  1. chemical change

  2. physical change

  3. neutralisation

  4. galvanisation

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Correct Option: B
Explanation:

The process of obtaining salt by the evaporation of sea water is a process of crystallization which is a reversible process and a physical change, these crystals will convert again in salt solution (seawater) by dissolving them in water.


Hence the correct option is B.

Which of the following is a physical change?

chemistry change around us physical changes changes and their classification physical changes

  1. Photosynthesis

  2. Melting of steel

  3. Burning of wood

  4. Radioactive decay

Show answer
Correct Option: B
Explanation:

Solution:- (B) Melting of steel

Explanation:-
Melting is the physical change, temperature and melting points are physical properties.