Maharashtra Board Class 6 Science Solution Chapter 6 – Substances in Daily Use
Balbharati Maharashtra Board Class 6 Science Solution Chapter 6: Substances in Daily Use. Marathi or English Medium Students of Class 6 get here Substances in Daily Use full Exercise Solution.
|Maharashtra Class 6|
Substances in Daily Use
1.) Fill in the blanks using proper words.
a.) Rubber made by vulcanization is a man- made material.
b.) Man-made materials are made by processing natural materials.
c.) Nylon thread was developed simultaneously in New York and London.
d.) Rayon is also known as synthetic silk.
2.) Answer the following questions.
a) Why did the need for man- made materials arise?
Humans always aspired for attaining new things and wanted to live a comfortable life.
With their tremendous effort, man not only began to use natural substances but also learnt to make new substances by processing them. These substances are quite easy to use and an abundant amount of these substances can be made accessible at an affordable price. As a result of which, these substances were used on a large scale basis. Nowadays, a great deal of man-made substances are used on a regular basis. These are the primary reasons that have contributed to an increase in the use of man – made materials.
b) Which are the natural materials obtained from plants and animals?
Jute and cotton are the natural materials that are obtained from plants and leather and wool are the natural materials that are acquired from animals.
c) What is vulcanization?
Vulcanization refers to a process which are mainly used for the purpose of manufacturing rubber. In this procedure, rubber is heated for a period of three to four hours,along with the mixture of sulphur. The quantity of sulphur that are added in the mixture usually varies, in accordance with the purpose for which the rubber will be used. Erasers and rubber balls are two such examples.
d) Which natural materials are used to obtain fibres?
In order to obtain fibres, natural materials like wool and silk are mainly used, which are acquired from animals. Cotton and jute are the natural materials of plant origin that are mainly used for the purpose of obtaining fibres.
3) What are we used for?
a.) Soil – 1.) Soil is mainly used as a construction material.
2.) It is used in cosmetics.
3.) It is also used for medicinal purposes.
b.) Wood – 1. Wood is mainly used for manufacturing furniture.
2.) Wood is used as a primary source of fuel.
3.) Wood is also used for making weapons.
c.) Nylon – 1. Nylon is used for the purpose of manufacturing clothes .
2.) Nylon is also used for making fishing nets and ropes.
d.) Paper – 1. Paper is mainly used for the purpose of packaging.
2.) Paper is also used for making books and newspapers.
d) Rubber – Rubber is used for making rubber balls, erasers and rubber toys.
4.) How is paper manufactured ? Write in your own words.
Pine trees are mainly used for manufacturing paper. First, the bark of the trees are removed and then wood is smashed into several tiny pieces. The pieces of these woods are mixed with some form of chemicals, which are then soaked for a quite long period of time. This process helps in the formation of pulp. After the completion of the chemical process, the fibrous substances are removed from the wood pulp and mixed with some dyes. Then, there is passing of pulp with the help of rollers, which are then dried in order to form paper and lastly, the papers are winded on reels . Paper and wood are interrelated. In order to save trees, it is essential to use paper conservatively.
5.) Give scientific reasons.
a.) We must use cotton clothes in summer.
Cotton clothes must be used in summer because it helps us in protecting ourselves from the scorching heat of the sun. It helps to keep ourselves cool, by absorbing the sweat from our body. Cotton clothes are made in such a way, that it permits easy circulation of air, which enables us to retain a cooling effect.
b.) We must observe economy in the use of materials.
It is essential to observe economy in the use of materials because they bring about an impact to our environment. As the growth of population is increasing in a rapid manner, so as a result of which, there is also an increase in demand for these natural resources. So, these natural resources must be used conservatively in order to sustain ecological balance and also to conserve them for our subsequent generations . Most of the natural resources that are acquiredfrom our environment falls under the category of non- renewable resources. Several man -made substances that we use today are mainly non – biodegradable in nature. If man made -materials are used on a large scale basis , then it will bring about a harmful effect to our environment. Therefore, these points illustrates the importance of using materials in a judicial manner.
c.) Saving paper is the need of the hour.
We are aware of the fact that, paper is acquired from trees. Trees are considered as a valuable resources because it not only gives us paper but it also provides us with oxygen which is necessary for our survival. They also play an important role in maintaining the climatic condition. A large quantity of trees are chopped down, for the purpose of making papers. So, we must use papers in a judicial manner, without wasting it unnecessarily.As we all know, that deforestation canbring about a harmful impact on our environment. So , we must make tremendous effort to save papers by taking effective steps which will ultimately bring about a great difference.
d.) Man – made materials have more demand.
Most of the man- made materials can be used very easily and an ample quantity of these materials can be obtained at a reasonable price. So for this reason, the man – made materials have huge demand.
e.) Humus is a natural material.
Humus is formed through a natural process, so it is considered as a natural material. It is the organic matter of soil, which contains rich source of nutrients. The process of decomposition takes place, where the decomposer plays an important role in converting dead plants and animal matters into humus, that are used by other plants. This enhances the rate of soil fertility.
6.) Find out.
1.) How is lac obtained from nature?
Lac is a resinous substance that are obtained from animal origin. Lac insect plays an important role in secreting these resinous substances. These insects are cultured for the purpose of obtaining lac and this process is commonly known as lac- culture. The lac insects mostly feed on the sap of various trees and bushes and it dwells as a parasite. The moment the lava of the insects settles down on the plant, it gives rise to lac secretion. Primarily, lac depicts a lustrous appearance but gradually it becomes harder when it is exposed to air. This lac is then used for the purpose of manufacturing jewellery.
2.) How are pearls obtained?
Pearls constitutes the most expensive jewels that are formed by a living organism. When a microscopic foreign matter finds its path inside a oyster , it leads to the formation of pearls . Nacre , is a substance that are used by the animal in coating the object. The pearl is formed when various layers of nacre compiles above the foreign matter for quite long duration of time. These oysters are mostly found in seas and they are opened for the purpose of collecting pearls.