What is the difference in these two situations?
a. A balloon is inflated by blowing air into it.
b. A balloon bursts when inflating it.

Important Questions on Changes Around Us

MEDIUM

6th CBSE

IMPORTANT

Sciwise - A coursebook of Science>Chapter 6 - Changes Around Us>EXERCISE>Q 3

Why does the composition of the product changes after a chemical change?

HARD

6th CBSE

IMPORTANT

Sciwise - A coursebook of Science>Chapter 6 - Changes Around Us>EXERCISE>Q 4

What is a chemical change? Support your answer giving two examples.

MEDIUM

6th CBSE

IMPORTANT

Sciwise - A coursebook of Science>Chapter 6 - Changes Around Us>EXERCISE>Q 5

Give two examples each of situations where contraction and expansion of materials around you play an important role.

HARD

6th CBSE

IMPORTANT

Sciwise - A coursebook of Science>Chapter 6 - Changes Around Us>THINK AND ANSWER>Q 1

Due to increase in global temperature (global warming), large sheaths of ice are melting in the Arctic regions of the Earth. How can we contribute in our own ways to resist this change and reduce the heating of our Earth?

HARD

6th CBSE

IMPORTANT

Sciwise - A coursebook of Science>Chapter 6 - Changes Around Us>THINK AND ANSWER>Q 2

On heating water, a gas (vapour) is produced. Similarly, when passing electricity through water, hydrogen and oxygen gases are produced. Can we say that both the processes are same? Why or Why not?

HARD

6th CBSE

IMPORTANT

Sciwise - A coursebook of Science>Chapter 6 - Changes Around Us>THINK AND ANSWER>Q 3

What made iron a popular metal for weapons and tools around $1200$ BC?

(Hint - Iron turns into steel by heating with carbon)

How did the change, in this case, lead to advancement of human society?

HARD

6th CBSE

IMPORTANT

Sciwise - A coursebook of Science>Chapter 6 - Changes Around Us>DISCUSS>Q 1

Ramesh had a cement bag which got wet in rain at night. The next day, he kept that bag in the sunlight to dry. Do you think the change which occurred in the cement could be reversed?

MEDIUM

6th CBSE

IMPORTANT

Sciwise - A coursebook of Science>Chapter 6 - Changes Around Us>DISCUSS>Q 2

Dissolving sugar or salt in water is considered as a physical and reversible change. Salt or sugar when dissolved, completely disappear in water to make a solution. Then, how is it possible to get salt or sugar back from the solution?