English Medium Class 10 - CBSE Question Bank Solutions for Science

What would be the electron dot structure of a molecule of sulphur which is made up of eight atoms of sulphur? (Hint – the eight atoms of sulphur are joined together in the form of a ring.)

Ethane, with the molecular formula C₂H₆ has ______.

Butanone is a four-carbon compound with the functional group:

Explain the nature of the covalent bond using the bond formation in CH₃Cl.

What are trophic levels? Give an example of a food chain and state the different trophic levels in it.

Which of the following constitute a food-chain?

What will happen if we kill all the organisms in one trophic level?

Will the impact of removing all the organisms in a trophic level be different for different trophic levels? Can the organisms of any trophic level be removed without causing any damage to the ecosystem?

What is biological magnification?

In the following food chain, 100 J of energy is available to the lion. How much energy was available to the producer?

Plants → Deer → Lion

In the following food chain, plants provide 500 J of energy to rats. How much energy will be available to hawks from snakes?

Plants → Rats → Snakes → Hawks 

In the following food chain, 20,000 J of energy was available to the plants. How much energy would be available to man in this chain?    
Plants → Sheep → Man

Explain how the pesticides enter a food chain and subsequently get into our body.

2 mL of sodium hydroxide solution is added to a few pieces of granulated zinc metal taken in a test tube. When the contents are warmed, a gas evolves which is bubbled through a soap solution before testing. Write the equation of the chemical reaction involved and the test to detect the gas. Name the gas which will be evolved when the same metal reacts with dilute solution of a strong acid.

 Why are most carbon compounds poor conductors of electricity?

Why are plants called producers?

What name has been given to those organisms which break down the complex organic compounds present in dead animals and plants?

What are planktons?

The following statement is true or false :
 In biology, human beings are called producers.

The following statement is true or false :

Secondary consumers and tertiary consumers, both are carnivores.