Tag: substances and objects

Questions Related to substances and objects

Which of the following is/are different ways to bring a change?

chemistry changes around us can all changes be reversed? substances and objects classification of changes

  1. Expansion

  2. Contraction

  3. Evaporation

  4. All of the above.

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Correct Option: D
Explanation:

All of the following is/are different ways to bring a change.
Expansion, Contraction, Evaporation,Melting.

What are the different conditions for a chemical reaction to take place?

chemistry changes around us can all changes be reversed? substances and objects classification of changes

  1. Heating

  2. Mixing

  3. Boiling

  4. All of the above

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Correct Option: D
Explanation:

D, Temperature and close contact plays important roles in chemical reactions. These factors affects the activation energy of the reaction.

In the tools which are used to dig the soil, the iron blade in these tools fixed to the wooden handle. Which of the following is used during the change?

chemistry changes around us can all changes be reversed? substances and objects classification of changes

  1. Expansion

  2. Contraction

  3. Both expansion and contraction.

  4. Neither expansion and contraction.

Show answer
Correct Option: C
Explanation:

Both expansion and contraction is used during the change.
The iron blade has a ring in which the wooden handle is fixed. The ring is slightly smaller in size than the wooden handle.The ring is heated and it becomes slightly larger in size (expands). The handle  fits into the ring. When the ring cools it contracts and tightly fits on the handle.

The iron blade has a ring in which the wooden handle is fixed. The ring is slightly smaller in size than the wooden handle.
The ring is heated . When the ring cools it _____ and tightly fits on the handle.

chemistry changes around us can all changes be reversed? substances and objects classification of changes

  1. contracts

  2. expands

  3. evaporates

  4. condenses

Show answer
Correct Option: A
Explanation:

The iron blade has a ring in which the wooden handle is fixed. The ring is slightly smaller in size than the wooden handle.
The ring is heated and it becomes slightly larger in size (expands). The handle  fits into the ring. When the ring cools it contracts and tightly fits on the handle.