Can you suggest some changes in your school which would make it environment-friendly?
Some changes we can make in our school which would make it environmental- friendly. These are following:-
1. Plantation of the trees around the school campus, make loan to sit in the ground that will be more comfortable for the kids as well as the teachers.
2. We should switch off our lights, fans television and energy or light appliances when they are not in use.
3. Putting solar panels on the roof of the school instead of using generator because solar panel generators are silent and have no moving parts. Generators produce high amount of noise that comes from gas or diesel powered machines. Solar panels require less maintenance than generators.
4. By avoiding water waster while we are drinking.
5. By separating degradable or non- biodegradable wastes.
6. There can be more windows for saving the electricity bill or for the natural light consumption.
7. Reusing the paper for writing on both the sides or we can use pencil for the rough work so that we can use the paper for the multiple times.
Find out about the traditional systems of water harvesting/management in your region.
Suggest some approaches towards the conservation of forests.
We saw in this chapter that there are four main stakeholders when it comes to forests and wildlife. Which among these should have the authority to decide the management of forest produce? Why do you think so?
List five things you have done over the last one week to —
(a) conserve our natural resources.
(b) increase the pressure on our natural resources.
Find out the source of water in your region/locality. Is water from this source available to all people living in that area?
How can you as an individual contribute or make a difference to the management of (a) forests and wildlife, (b) water resources and (c) coal and petroleum?
Why should we conserve forests and wildlife?
Compare the above system with the probable systems in hilly/mountainous areas or plains or plateau regions.
What changes can you make in your habits to become more environment-friendly?
What can you as an individual do to reduce your consumption of the various natural resources?
Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
What is a good source of energy?
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
What is the difference between a reflex action and walking?
What is the importance of DNA copying in reproduction?
If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?
Why should a magnesium ribbon be cleared before burning in air?
Define the principal focus of a concave mirror.
You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?
You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.
10 mL of a solution of NaOH is found to be completely neutralised by 8 mL of a given solution of HCl. If we take 20 mL of the same solution of NaOH, the amount HCl solution (the same solution as before) required to neutralise it will be
(a) 4 mL (b) 8 mL (c) 12 mL (d) 16 mL
What are oxidising agents?
How can ethanol and ethanoic acid be differentiated on the basis of their physical and chemical properties?
How does reproduction help in providing stability to populations of species?
Why does menstruation occur?
In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved.
An object of size 7.0 cm is placed at 27 cm in front of a concave mirror of focal length 18 cm. At what distance from the mirror should a screen be placed, so that a sharp focussed image can be obtained? Find the size and the nature of the image.
A positively-charged particle (alpha-particle) projected towards west is deflected towards north by a magnetic field. The direction of magnetic field is
(a) towards south (b) towards east
(c) downward (d) upward
Which gas is produced when dilute hydrochloric acid is added to a reactive metal? Write the chemical reaction when iron reacts with dilute H2SO4.