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Cellulose is a common part of fibres such as coir and jute. But starch is not, why?

Cellulose is a common part of fibres such as coir and jute. But starch is not, why?

Biology kvkanjikodelibrary January 20, 2021

Starch and cellulose are two very similar polymers. In fact, they are both made from the same monomer, glucose, and ha…

What do the atomic numbers found on the periodic table of the elements indicate?

What do the atomic numbers found on the periodic table of the elements indicate?

Chemistry kvkanjikodelibrary December 26, 2020

The atomic number of an element suggests the number of protons in the nucleus of that element. You know the number of …

Is there any substance which changes its state from liquid to solid when we heat it?

Is there any substance which changes its state from liquid to solid when we heat it?

Chemistry kvkanjikodelibrary December 16, 2020

When you heat a solid, you expect it to melt and when you boil water, you can be pretty certain that it will turn into …

What is the salt, which when present in excess in drinking water can cause discolouration of teeth?

What is the salt, which when present in excess in drinking water can cause discolouration of teeth?

Biology kvkanjikodelibrary December 16, 2020

Excessive ingestion of fluorides during early childhood may damage tooth-forming cells, leading to a defect in the ena…

What will happen if you soak a raw egg in vinegar for 24 hours?

What will happen if you soak a raw egg in vinegar for 24 hours?

Chemistry kvkanjikodelibrary December 13, 2020

The shell of a chicken egg is made up of calcium carbonate. When an egg is soaked in vinegar for a long time, it start…

Why is pure iron not suitable as an engineering material?

Why is pure iron not suitable as an engineering material?

Chemistry kvkanjikodelibrary December 12, 2020

Pure iron is not suitable as an engineering material because it lacks sufficient strength and also rusts quickly. The …

How do BHT and BHA preserve fatty food?

How do BHT and BHA preserve fatty food?

Biology kvkanjikodelibrary December 11, 2020

Butylated hydroxyanisole (BHA) and Butylated hydroxytoluene (BHT) are antioxidants, which keep oil from going off. Oxy…

Which is the hardest mineral in the body?

Which is the hardest mineral in the body?

Biology kvkanjikodelibrary November 26, 2020

It is calcium phosphate, which forms tooth enamel. Like bones, tooth enamel is made from crystals of calcium phosphate…

What is the alternative name for mercury?

What is the alternative name for mercury?

Chemistry kvkanjikodelibrary November 09, 2020

Mercury is also called quicksilver because of its silver like lustre. It has the symbol Hg (from the Greek hydrargyrum…

Why is it that iron plates rust and crumble, whereas aluminium plates do not?

Why is it that iron plates rust and crumble, whereas aluminium plates do not?

Chemistry kvkanjikodelibrary November 08, 2020

Rust formation is actually oxidation of the metal. The exposed surface of a metal plate gets oxidised –– for example, …

What is the substance that burns in a matchstick?

What is the substance that burns in a matchstick?

Chemistry kvkanjikodelibrary November 07, 2020

A match consists of three basic parts: the head, the tinder and the handle. The head contains more than twenty chemica…

Why is DDT banned in most countries?

Why is DDT banned in most countries?

Biology kvkanjikodelibrary November 06, 2020

DDT stands for Dichloro-diphenyl trichloroethane. It is very effective as an insecticide but is very toxic to fish, s…

Name the two elements that are the most abundant in the human body. What are their percentage weights?

Name the two elements that are the most abundant in the human body. What are their percentage weights?

Biology kvkanjikodelibrary November 05, 2020

Oxygen at 65% is the most abundant and carbon is next at 18.5%. 96.2% of the body weight of a human comes from ‘organi…

What is reverse osmosis?

What is reverse osmosis?

Biology kvkanjikodelibrary November 04, 2020

Diffusion is the movement of molecules from a region of higher concentration to a region of lower concentration. Osmos…

What is tear gas?

What is tear gas?

Chemistry kvkanjikodelibrary October 24, 2020

Tear gases are irritants –– they irritate mucous membranes in the eyes, nose, mouth and lungs, and cause watering of ey…

What determines the color and quality of fireworks?

What determines the color and quality of fireworks?

Chemistry kvkanjikodelibrary October 23, 2020

Pure colors require pure ingredients. Even trace amounts of sodium impurities (yellow-orange) are sufficient to overpow…

Why is soap bubble always spherical in shape, even when using a square shaped bubbler?

Why is soap bubble always spherical in shape, even when using a square shaped bubbler?

Chemistry kvkanjikodelibrary October 09, 2020

The attractive force of surface tension causes the bubbles to take spherical shape. Because a sphere has the smallest s…

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