Class 8 Science Chapter 3 MCQ

Here, all these statements are correct. Hence, your answer will be option [D].

About 300 million years ago the earth had dense forests in low lying wetland areas. Due to natural processes, like flooding, these forests got buried under the soil. As more soil deposited over them, they were compressed. The temperature also rose as they sank deeper and deeper. Under high pressure and high temperature, dead plants got slowly converted to coal. As coal contains mainly carbon, the slow process of conversion of dead vegetation into coal is called carbonisation.

Here, all these statements are correct. Hence, your answer will be option [D].

Resources which are present in unlimited quantity in nature are called in-exhaustible natural resources.

Oxygen in air is an exhaustible natural resource. The natural resources which are present in unlimited quantity in nature and are not likely to be exhausted by human activities are called “inexhaustible natural resources”. Examples of inexhaustible natural resources are: sunlight, air, water. They last forever. The resources which are present in a limited quantity in nature and can be exhausted by human activities are called “exhaustible natural resources”. The example of exhaustible natural resources is: coal, petroleum and natural gas, mineral, forest and wildlife etc. They do not last forever.

Naphthalene balls are used to repel moths and other insects (in stored clothes, etc.)

Coal is the substance obtained by carbonization. Rest of all statements are correct. Hence, your answer will be option [D].

Coal is formed by the carbonization of dead vegetation.

Here, all these statements are correct. Hence, your answer will be option [D].

Coal is formed by the decomposition of large land plants and trees buried under the earth about 300 million years ago.

Here, all these statements are correct. Hence, your answer will be option [D].

Fossil fuels are obtained from the remains of living organisms (plants and animals) buried under the earth millions of years ago. Note: Coal, Petroleum and Natural gas are fossil fuels.

The most common fuel used in homes is liquefied petroleum gas because it is obtained from petroleum and it is liquefied by compression before filling into the gas cylinders. Liquefied Petroleum Gas consists mainly of butane. LPG burns easily and it does not produce any poisonous gas on burning. LPG burns with a smokeless flame and hence does not cause air pollution.

Here, all these statements are correct. Hence, your answer will be option [D].

CNG (Compressed Natural Gas) is not obtained from coal. Note: Natural gas is formed under the earth by the decomposition of vegetable matter lying under water.

In the oil refinery, crude petroleum oil is refined into different useful fractions. The separation of petroleum called “fractional distillation”. In another words, fraction of petroleum which having different boiling point ranges are collected separately. The various useful fractions obtained by the refining of petroleum are: gas, petrol, kerosene, diesel, lubricating oil, paraffin wax etc.

Wildlife and minerals are exhaustible natural resources because these resources are present in a limited quantity in nature and can be exhausted by human activities.

The major component of LPG and CNG are butane and methane respectively.

Here, all these statements are correct about fossil fuel. Hence, your answer will be option [D].

Natural gas is stored under high pressure as compressed natural gas. Note: It is easy to transport natural gas through pipes and it can be used directly for burning in homes where it can be supplied through pipes. Natural gas is used for power generation

Sunlight, air and water are the examples of inexhaustible nature resources. There is a never ending in nature and they can be used again and again. But coal, petroleum and natural gas are non-renewable resources of energy. By using or exhausted, no more supply of these fuels will be available in the near future.

Coal is used to make coke, not Coca-Cola. Coke is an almost pure form of carbon. Coal is important because it can be used as a source of heat energy. Coke is a porous and tough, black solid substance. Coke is prepared by heating coal in the absence of air. Coke is used in the manufacturing of “steel”. Although, coke burns without producing any smoke whereas coal produces a lot of smoke on burning.

Coke is prepared by heating coal in the absence of air. Coke is mainly used as a reducing agent in the extraction of metals. Such as iron, zinc etc. Coke is used in the manufacturing of Steel.

Coal tar is black liquid which have unpleasant smell and obtained from coke. Although, coal tar is a not a single compound, it is a mixture of 200 types of carbon compounds. Such as, benzene, naphthalene, phenol etc.

The world’s first oil well was drilled in Pennsylvania, USA, in 1859. Eight years later, in 1867, oil was stuck at Makum in Assam. In India, oil is found in Assam, Gujarat, Mumbai High and in the river basins of Godavari and Krishna.