Types of Natural Resources for Class 3 EVS
Resources that we get from nature and are used by man for various purposes are called natural resources. Natural resources can exhaust over time or can be used again and again. For example, wind used to produce energy is an inexhaustible resource, whereas fossil fuels are an exhaustible resource. Nature has enough types of natural resources for our needs. However, while harnessing natural resources, one should consider the idea of sustainable development, i.e., ensuring sufficient resources are left for future generations.

Things We Get from Nature
Question 1:
Salt and Petrol Are Both Natural Resources That We Use Regularly. But Why Is Salt Cheaper Than Petrol?
Answers:
- Natural resources need to be extracted and processed before use.
- Salt is mostly available from seawater. It is separated from seawater by the process of evaporation.
- On the other hand, petrol is a crude oil product that needs to be extracted from the depths of the Earth.
- It needs to be processed by the process of fractional distillation. Also, it is one of the non-renewable resources and hence not cheap.


Question 2:
Will It Be Possible to Stay Alive Without Using Any Natural Resources?
Answers:
- Things like food, garments, fuel, etc., are needs we cannot neglect.
- All these things come from nature. These are made using natural resources as raw materials.
- Hence, it is not possible to live without natural resources.
Question 3:
If Plastic Is a Cheaper and More Durable Resource, Then Why Is It Banned? Give Examples of the Substances That Can Be Used Instead of Plastic.
Answers:
- Although plastic is a cheaper and more durable resource, it is banned because it is a non-biodegradable material.
- As a result, it causes drainage problems and accumulates in the water bodies.
- It also releases harmful chemicals into the soil.
- Cotton cloth, jute, and paper can be used instead of plastics.
- Nowadays, biodegradable plastic is also available.
Renewable and Non-Renewable Resources
Question 1:
The Municipal Officers Recently Cut Some Trees Along the Main Road. Will They Grow Again?
Answers:
- Yes, municipal officers mostly cut the branches of trees before the rainy season to avoid accidental falling of branches on the road.
- When trees are cut up to a certain height leaving their trunk and roots unharmed, they can grow again.

Question 2:
If We Are Receiving Rainfall Every Year, Why Are People Digging Deeper and Deeper Into Borewells?
Answers:
- The rains are getting irregular and less frequent every year. People are relying on groundwater as a resource.
- Due to overuse, the aquifers that collect the rainwater runoff under the ground are getting dry.
- So, people in search of water, dig deeper and deeper into borewells.

Question 3:
What Is Overgrazing? Why Does It Harm Nature?
Answers:
- Eating grass by cattle to such an extent that it cannot replenish or regrow is called overgrazing.
- Soil covered with grass is less prone to erosion.
- The soil not covered by vegetation loses its nutrients due to erosion and becomes infertile.
- Hence overgrazing harms nature.

Question 4:
Can We Make Liquid Fuel From the Smoke From the Vehicles?
Answers:
- No, the liquid fuel is oxidised to produce heat and energy.
- This change is permanent and cannot be reversed.

Importance of Plants
Question 1:
Is a Tomato a Fruit or a Vegetable?
Answers:
- Tomato is a fruit that grows on the tomato plant.
- A tomato flower matures to get converted into a fruit with seeds in it.

Question 2:
Is a Tomato a Fruit or a Vegetable?
Answers:
- Plants perform photosynthesis only in the presence of sunlight during, which they release oxygen. At night they respire like animals and hence, produce carbon dioxide.
- But some plants such as Tulsi, Peepal, Aloe vera, Neem, etc., also release some amount of oxygen at night time.

Question 3:
Other Than Burning Wood, Will It Be Possible to Make Fuel Out of Plants?
Answers:
- It is possible to generate fuel from plant and animal waste.
- Ethanol and biogas are examples of such fuels.
- Biofuels burn with less or no smoke and hence, cause less pollution.
Question 4:
Is It True That Forests Attract Rain? How?
Answers:
- Plants release water in the form of water vapour by the process of transpiration.
- More the number of trees higher is the rate of transpiration.
- Hence, an area covered with forest receives more rainfall as the amount of water vapour increases in the air.

Solar Energy
Question 1:
Does Solar Energy Cause Pollution? Give Reason for Your Answer.
Answers:
- Solar energy directly provides light and heat energy to us.
- In this process, there is no production of smoke or residue which may cause pollution.
Question 2:
Is It Because of the Sun That We Face Hotter and Hotter Summers Yearly?
Answers:
- Sun is the source of heat and light on Earth.
- But the gradual increase in temperature during summer is because of the rise in carbon dioxide levels in nature.
- Carbon dioxide can absorb heat; hence, an increase in its level leads to higher temperatures.