C-08 — Our Resources

Which natural resource grows plants and produces crops?

Soil is the source of all the following resources EXCEPT —

The substances present in soil are divided into how many groups?

Which is NOT one of the four groups of substances in soil?

Minerals present in soil are usually —

Which is one of the main minerals in soil?

Which element is present only in small amount in soil?

Which is NOT a main mineral of soil?

The blackish coloured organic substance present in soil is called —

Humus is formed from —

Which is NOT a component of humus?

According to Fig. 8.01, percentage of inorganic substance in soil is —

Percentage of water in normal soil composition is —

Percentage of organic substance in soil composition is —

Percentage of gaseous substances in soil is —

Water in soil is mainly present in —

The water retaining capacity of soil depends on —

Between sand and clay, which retains more water?

Why does clay retain more water than sand?

Sandy soil has higher drainage because —

Humus retains water that —

Water content in protoplasm of plant cells is about —

Plants absorb a small part of water through —

Major part of water needed by plants comes from soil through —

Water obtained from soil is mainly utilised by plants for —

Nutrients like nitrogen and phosphorus are taken up by plants —

Exchange of gases between soil and atmospheric air is called —

Which gas is NOT usually present in soil pores?

Aerobic microorganisms in soil need —

Oxygen in soil chemically helps to —

Soil is divided into how many horizontal layers?

Each horizontal layer of soil is called —

The topmost layer of soil is known as —

Top Soil is another name for —

Biodegradation of dead plants and animals starts in —

The soil in Horizon A is usually —

Sub Soil refers to —

Horizon B is full of —

Soft rocks formed first from the hard parent rocks are present in —

Soil is produced from rocks through —

Just below Horizon C lies —

Consider the following statements about soil:

Soil is divided into how many main categories based on composition and water holding?

Which is NOT one of the four main types of soil?

Loamy soil is created by combination of —

The largest particle size is found in —

Which soil has the highest water holding ability?

Drainage of sandy soil is —

Best aeration is found in —

Crops needing a huge amount of water do NOT grow well in —

Sandy soil is suitable during heavy rainfall water logging because —

Why can balls not be made with wet sandy soil?

The most fertile soil is —

When rubbed between fingers, which soil feels smooth and sticks to fingers?

A common mineral found in silt soil is —

Clay soil particles are —

Water logging easily occurs in —

Clay soil is used for —

The most suitable soil for cultivation is —

Loamy soil is good for cultivation because —

Peaty soil is basically formed due to —

Peaty soil is usually available in —

Chalky soil is —

From which soil can mineral nutrients like iron and magnesium not be transported to plants?

Why is the nutrient content of peaty soil relatively low?

Consider the following about clay soil:

Most of the crops grow well if the soil pH is maintained around —

Potato and wheat give highest production in pH range —

Barley grows well in soil of pH —

By measuring pH we can assess whether a land is —

Soil pH should be checked —

In our country, solid waste in municipal areas is managed mainly by —

After disposal, wastes undergo biodegradation and turn into —

Which toxic metal in industrial waste kills beneficial microorganisms in soil?

Which is NOT a toxic substance commonly found in industrial waste?

Decomposition of proteins and amino acids in waste by bacteria produces —

Which toxic gas is NOT produced from waste decomposition?

Toxic chemicals enter human or animal body mainly through —

Radioactive substances polluting soil come from —

Which is NOT a radioactive substance polluting soil?

Radioactive substances cause cancer in —

The Chernobyl accident is related to —

Excessive siltation on agricultural land —

A major source of soil particles in siltation is —

Mining operation pollutes soil mainly by —

Conflagration is a common accident in —

Which causes soil pollution?

Animal and human excreta cause soil pollution because they contain —

Consider the following statements about soil pollution:

Which is NOT a cause of soil erosion?

The recent landslide in Chittagong area was caused mainly by —

The most fruitful strategy to conserve soil is —

During harvest, we should NOT —

Which plant species is mentioned to prevent erosion on slopes?

For cultivation we should use, instead of chemical fertilisers —

Cultivating the same crop repeatedly in the same land —

River bank erosion in strong-current rivers can be prevented by —

Roots of trees prevent soil erosion because —

About how many different types of minerals have been identified in nature?

Which is a metallic mineral?

Which is a non-metallic mineral?

Coal, gas and petroleum are classified as —

Magnetite ($\ce{Fe3O4}$) is used in —

Chemical formula of limestone is —

Limestone is NOT used in —

Limestone is used to adjust pH of —

Chemical formula of quartz is —

Quartz is used in —

Silver is used to make —

Mica is used as —

Chemical formula of gypsum is —

Gypsum is used as raw material of —

Metal pyrites are used to manufacture —

Gold and diamond are mainly used to make —

Gas, coal and petroleum are used as —

Minerals are usually —

Graphite and diamond have the same chemical composition but differ in —

The softest mineral is —

The hardest mineral is —

Talc is used to manufacture —

Graphite is used as —

Most metallic minerals show lusture similar to —

Specific gravity range of most minerals is —

Cleavage of a mineral indicates —

Minerals of higher hardness can —

Chemical properties of a mineral depend on —

The major natural fuels used in Bangladesh are —

Which is NOT a natural fuel mentioned in the chapter?

The main component of natural gas is —

Chemical formula of methane is —

Which is NOT present in small amount in natural gas?

Which trace gas is NOT found in natural gas?

According to the most accepted theory, natural gas was formed from —

Natural gas was formed about —

High temperature and pressure on buried organic matter caused loss of —

Natural gas and petroleum are composed of —

The gas reserve formed underground is called —

Processing of natural gas usually begins at —

The first step in natural gas processing is —

After separating petroleum oil, the next step is to compress and separate —

Water is removed from natural gas by passing through —

Impurities removed during gas processing include —

After all processing, the pure gas obtained for pipeline is —

Percentage of natural gas used as raw material for urea fertiliser in Bangladesh is —

Percentage of natural gas used for electricity production is —

Percentage of natural gas consumed in industry is —

Percentage of natural gas used in domestic purpose is —

System loss of natural gas in Bangladesh is about —

Natural gas has been used as fuel in vehicles in Bangladesh since —

The natural gas reserve we have is —

Petroleum is —

Propane and butane are included in petroleum because they —

Normal conditions for propane/butane phase reference are —

Which is NOT considered petroleum?

Crude petroleum contains impurity of —

Refining of crude oil is done by —

Crude oil is refined by heating at about —

Major part of petroleum is used as —

Diesel engines use petroleum for purposes including —

Petroleum is also used in industry for —

Coal is a —

The main chemical element in coal is —

Besides carbon, coal contains variable amounts of —

Coal was formed from —

Coal was formed about how long ago?

Initial wet, spongy, porous and humus-like material before coal is called —

Three types of coal are —

The oldest and hardest coal is —

Anthracite coal contains carbon of approximately —

Bituminous coal is about —

Carbon content in bituminous coal is —

Lignite coal is about —

Maximum carbon content in lignite coal is —

The two methods of coal mining are —

Most coal layers occur near earth surface, so the mining method mostly used is —

Coal is transported from ground to processing plant by —

Impurities removed during coal processing include —

In Bangladesh, coal is mostly used in —

Goldsmiths and blacksmiths use coal to —

To conserve natural fuels we should increase use of —

Consider the following statements:

Which one of the following is the softest mineral?

Consider the following about soil of the subsoil layers:

Which layer of soil contains rock particles?

Crop production is good in the topmost layer because this soil —

What is aeration?

Among Seema (water-holding, very fine particle soil), Bokul (mixed with rocks, larger particles) and Shahin (small particles rich in organic and mineral), whose area's soil is suitable for making household pottery?

Between Bokul (sandy with rocks) and Shahin (silt rich in organic and mineral), whose area will produce more crops?

What is meant by fossil fuel?

Why can't the substances present in soil be easily separated?

Why doesn't top soil contain mineral substances?

Why does oil obtained from mines need to be refined?

Can balls be made using sandy soil?