Chapter 24 Substances, Objects and Energy Solutions

Maharashtra State Board Class 5 EVS Solutions Part 1 Chapter 24 Substances, Objects and Energy

5th Std EVS 1 Digest Chapter 24 Substances, Objects and Energy Textbook Questions and Answers

1. What’s the solution?

Question a.
We need to make a sherbet quickly for some guests. But we only have sugar candy in the house.
Answer:
We can pound sugar candy into a fine powder. When the powder is fine, it will quickly dissolve in water. Therefore we can make sherbet quickly.

Question b.
We need to rub salt on a corncob but only salt crystals are available.
Answer:
We can pound salt crystals. Either we can use mortar pestle or we can also crush the crystals of salt in a grinder. Such powdered salt can be easily applied on the corncob.

2. Use your brain power!

Question a.
Why do tablets of camphor decrease in size day by day ?
Answer:
Tablets of Camphor are in solid state. Camphor has a property to turn into gaseous state directly from a solid state. Therefore, camphor decreases in size gradually. One can also notice the fragrance of camphor as it turns into vapour.

Question b.
How do we save fuel by using public transport ?
Answer:
Each automobile vehicle needs fuel either in the form of petrol, diesel, or CNG. If all the people use a separate vehicle, the amount of fuel consumed would be much more. If many people start using public transport, fuel consumption would be reduced. A single bus or a train can carry many people and thus it can save lots of fuel.

3. Answer the following questions.

Question a.
When and why do clothes smell of naphthalene?
Answer:
The naphthalene balls are continuously converted into small particles in the gaseous state. These particles settle down on the clothes in which they are kept. Therefore if naphthalene balls are kept for a long time in the clothes, they smell of naphthalene due to these particles.

Question b.
In which states is water found in nature?
Answer:
Water is found in all three states in nature, solid, liquid and gaseous state. Ice is the solid state of water. Water in lakes, sea etc. are in liquid state and steam or vapour is the gaseous state of water.

Question c.
What is the difference between the solid, liquid and gaseous states of a substance?
Answer:
The differences in the solid, liquid and gaseous state of substances is given in the table below:

Question d.
What is meant by energy?
Answer:
The capacity to do the work is called energy.

Activities :

Fill in the blank with the correct answers from the options given below: