(i) Timber is used to build houses and in making furniture.
(ii) We use wood for these purposes due to their features like durability, stylish finishing and resistance to temperature changes.
(iii) Commercial timber is classified into hardwood and softwood.
(iv) Hardwood is used in construction work and in making furniture.
(v) Softwoods have a wide range of applications such as making plywood and paper making.

(i) Noise pollution affects the environment. Unpleasant or loud sounds distrub us. This is called as noise pollution.
(ii) Loud music the sounds of motor vehicles, fireworks and machines causes noise pollution.
(iii) Continuous noise disturbs our sleep and does not let us to study and also it make stress and health impacts.
(iv) It is also disturb animals, bird and whales in under water.
(v) To reduce noise pollution lower the volume when you watch TV or listen to music.
(vi) Remind drivers not to use the horm too much.
(vii) Avoid fire works and do not speak loudly.

Aim: Soap manufacturing.
Requirements:
i) 35 ml of water.
ii) 10 ml of NaOH.
iii) 60 ml of coconut oil.
Procedure:
i) Cover your work area with old newspaper.
ii) Take 35 ml of water in a jar.
iii) Add 10 gram of concentrated NaOH and allow it to cool.
iv) Then add 60 ml of coconut oil drop by drop and stir it well.
v) On getting dried, soap can be obtained.

(i) Direct collection and use of rain water is called rainwater harvesting.
(ii) Excellent and valuable source of water in emergencies.
(iii) Ideal solution for inadequancy of water.
(iv) Increase ground water level.
(v) Reduces rainwater run off and solves drainage problems in houses.

(i) Dr. Rajendra Singh is known as "Waterman of India".
(ii) He is a well - known water conservationist and environmentalist.
(iii) His team built rainwater storage tanks, check dams and other timetested as well as path - breaking techniques.
(iv) His team built over 8600 johads to collect rain water for all seasons. It has brought water back to over 1000 villages and revived five rivers in Rajasthan.
Awards:
(i) He won stockholm water prize in 2005, an award known as "The Noble Prize for water".
(ii) Ramon Magsaysay Award in 2001.
(iii) Jamnalal Bajaj Award in 2005.

i) Place the iron needle on a table. Now take a bar magnet and place one of its poles near one edge of iron needle and rub from one end to another end without changing the direction of the pole of the magnet. Repeat the process for 30 to 40 times.
ii) Bring a pin or some iron filings near the iron needle to check whether it has become a magnet. Does the iron needle attract the pin / Iron filing? If not continue the same process for some more time.

(i) If we remove an organism from the food chain leads to lack of energy transfer to higher trophic level organism and it will become to die.
(ii) So the entire ecosystem will affect.

Bio waste to compost preparation:
Step (i) : Acquire a bin.
Wooden bins or small pits are taken for the process.
Step (ii) : Prepare the bedding.
Soil or moist news papers are used as a bed.
Step (iii) : Add the worms.
Spread the worms on the bedding with moist newspaper.
Step (iv) : Bury food scraps under bedding.
Feed the worms with fruit and vegetable scraps.
Step (v) : Place a full sheet of dry newspaper on the top of the bedding.
Replace this sheet frequently.
Step (vi) : Choose a cover for the bin.
Cover the bin with a lid for about, 3-4 weeks with proper air contact.
Benefits of Vermi castings:
(i) Adds organic matter to the soil.
(ii) Soil absorbtion and retentivity of water is increased.
(iii) Helps to form soil aggregates.
(iv) Ease cultivation.

If we keep a strong bar magnet above the glass of water, all pins inside the water will come up due to its attraction towards the magnet.

Spices are aromatic part of some plants traditionally used to flavour the food.

(a) Loud Speaker - Noise pollution
(b) Plastic - Land pollution

Any substance that causes polution is known as pollutant. Chemicals, pesticides, smoke, crackers are the Pollutant.

i) In making black board chalks.
ii) In surgery for setting fractured bones.
iii) For making casts for statues and toys etc.
iv) In construction industry.

people get water from, canals, rivers, wells, ponds, water tanks, hand pipes for various purposes.

i) Free and open software is available at free of cost and can be shared to many end users.
ii) Free software is editable and customizable by the user and this leads to updation or development of new software.
iii) Examples of Free and Open source software are: LINUX, Open office, Geogebra etc.

(i) Neem trees give shadow and it purifies the air in the form of oxygen.
(ii) Leaves and other waste of this plant is used as fertilizer.
(iii) Oil and cake is derived from seeds of this plants is used as natural pesticides.
(iv) Juice of its leaves are used to treat pox like disease.

(i) Sewage should not be disposed off in rivers or oceans before treatment.
(ii) If we dispose sewage water before treatment the river and oceans will be polluted.
(iii) We can not use the river water for our day to day life.
(iv) Aquatic animals and species will die due to pollution.

(i) "To a thirsty man, a drop of water is worth more than a sack of gold".
(ii) "Water covers 2/3 of the surface of the earth. But only 0.002% is drinkable".
(iii) "Save water to secure for your future".
(iv) "Store water for dry days".
(v) "Save water, Save life".