Science questions in short. [2 marks ]

Petroleum was formed from dead organisms that got buried in the sea millions of years ago. These dead bodies got covered with layers of sand and clay. Lack of air, high temperature, and high pressure transformed these dead organisms into petroleum and natural gas.

The characteristics of coke are it is a tough, porous and black coloured substance. And it is almost pure form of carbon. The use of coke is in the manufacturing of steel and in the extraction of many metals.

Petrol and kerosene are the two products of petroleum which are used as fuels. Petrol: It is one of the products of petroleum which is used as motor fuel and aviation fuel etc. Kerosene: It is a product of petroleum which is used as fuel for stoves, lamps and jets.

When heated in air, coal burns and produces mainly carbon dioxide gas. Coal can be processed in industry to get some useful products such as coke, coal tar and coal gas. Coal is used as a fuel in industries and was used to cook food. It was used in railway engines to produce steam to run the engine. It is used in thermal power plants to produce electricity.

Petroleum was formed from dead organisms remain in the sea. Their bodies settled at the bottom of the sea. The bodies got covered with layers of sand and clay. Over millions of years, absence of air, high temperature and pressure changed the dead organisms into petroleum.

Carbonisation is the process by which plant material or vegetation buried deep under the earth was slowly converted into coal. Since, coal was formed from the remains of vegetation, it is also known as fossil fuel.

Exhaustible natural resources like coal, petroleum and natural gas were formed from the dead remains of living organisms. So these are called fossil fuels.

Paraffin wax and bitumen are the two products of petroleum which are not used as fuels.
Paraffin wax: It is one of the products of petroleum which is used for making ointments, candles, vaselines etc.
Bitumen: It is a product of petroleum which is used for paints and road surfacing purposes.

Naphthalene is used to repel moths and insects. We can say that it is used as an insecticide and pest repellent. Naphthalene is a white solid having a characteristic smell. It is obtained from coal tar which is a black thick liquid with an unpleasant smell.

The resources which can be used again and again are inexhaustible natural resources. Inexhaustible natural resources are the resources which are present in unlimited quantity in nature. These are not likely to be exhausted/end. They have a limitless supply. Examples are sunlight and air.

The name of a petroleum product which is used in dry cleaning is petrol. The other use of petrol is that it is used as s fuel in motors.

The exhaustible natural resources which are formed from the dead remains of living organisms or fossils are known as fossil fuels. For example, coal, petroleum and natural gas are fossil fuels. The resources are present in limited amount in nature and are known as exhaustible natural resources. They can be exhausted by human activities.

Substances used in everyday life which are manufactured starting from the products of coal tar are following: Synthetic dyes, drugs, perfumes, plastics and paints. Naphthalene balls used to repel moths and other insects are also obtained from coal tar.

The various resources like water, air, soil, vegetation, animals and minerals are obtained from nature. These resources are called natural resources.

We should use fossil fuels only when absolutely necessary because fossil fuels are non-renewable (exhaustible) source of energy. As we know that non-renewable resources are those resources whose amount in nature is limited. We have to save them now for our coming future generation and use them only when absolutely necessary.

Coke is a hard and dry fuel. It is prepared by heating bituminous coal (a type of coal) to a very high temperature in the absence of air. Coke has a high carbon content.

Coke is a very useful product of coal. It is a tough, porous and black substance. It is almost pure form of carbon. It is used as a reducing agent in the extraction of metals. It is also used in the manufacture of steel and in the extraction of many metals.

Renewable resources are also called inexhaustible natural resources. Sunlight and air are renewable resources. They both need to be conserved for a better future. We all need a clean air to breathe and a proper sunlight for our survival. Thus, renewable resources are needed to be conserved.

Many useful substances are obtained from petroleum and natural gas. These are termed as ‘Petrochemicals’. These are used in the manufacture of detergents, fibres (polyester, nylon, acrylic etc.), polythene and other man-made plastics. Hydrogen gas obtained from natural gas, is used in the production of fertilisers (urea).

The resources which are present in unlimited quantity in nature and are not likely to be exhausted by human activities are known as inexhaustible natural resources. For example, sunlight and air are inexhaustible natural resources.

Inexhaustible	Exhaustible
These are the resources which are present in unlimited quality in nature.	These are the resources whose amount in nature is limited.
Example: sunlight and air.	Examples: Forests, coal, petroleum etc.

The name of main fuels which are used for driving vehicles are:- Petrol: It is used as a fuel in light automobiles like motorcycle, cars, scooters etc. for driving. Diesel: It is used as a fuel in heavy motor vehicles like truck and tractors.

Petrol burns faster than coal because petrol instantly reacts with oxygen molecules when burnt in the presence of air whereas coal does not react instantly. Petrol is obtained from petroleum.

It takes a very long time for the formation of fossil fuels. It also requires specific conditions and it doesn’t happen quite often. Therefore, their limited stock will last only for a few hundred years.

Yes, it is possible to extract petroleum from under the sea. Petroleum was formed from dead organisms remain in the sea. Their bodies settled down at the bottom of the sea. The bodies got covered with layers of sand and clay. Over millions of years in the absence of air, high temperature and pressure changed the dead organisms into petroleum.

The fossil fuel such as petroleum is formed from the dead animals under the sea. As these organisms died, their bodies settled at the bottom of the sea. They got covered with layers of sand and clay. Over millions of years, in the absence of air, with high temperature and high pressure, these the dead organisms were transformed into petroleum and natural gas.

Decantation can be used to separate a mixture of petroleum and water. The mixture is allowed to stand. Petroleum is lighter than water, so it floats over water, Carefully, lighter layer of petroleum can be poured and separated without disturbing the heavier layer of water.

Petroleum is a dark oily liquid and have unpleasant smell. It is a mixture of various constituents. The process of separating various constituents like petroleum gas, petrol, diesel, lubricating oil, paraffin wax, etc. as fractions of petroleum is known as refining.

Diesel is one of the petroleum product used for electric generator. The other use of diesel is that it also used as a fuel in heavy motor vehicles.