English Medium कक्षा १० - CBSE Question Bank Solutions for Science

Why is sodium kept immersed in kerosene oil?

Write equations for the reactions of iron with steam. 

Write equations for the reactions of calcium and potassium with water.

Samples of four metals A, B, C and D were taken and added to the following solution one by one. The results obtained have been tabulated as follows.

Use the Table above to answer the following questions about metals A, B, C and D.

1. Which is the most reactive metal?
2. What would you observe if B is added to a solution of copper (II) sulphate?
3. Arrange the metals A, B, C and D in the order of decreasing reactivity.

Which gas is produced when dilute hydrochloric acid is added to a reactive metal? 

Write the chemical reaction when iron reacts with dilute H₂SO₄.

What would you observe when zinc is added to a solution of iron (II) sulphate? Write the chemical reaction that takes place.

Write the electron-dot structures for sodium, oxygen and magnesium.

Show the formation of Na₂O by the transfer of electrons.

An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be:

Food cans are coated with tin and not with zinc because ______.

You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.

Differentiate between metal and non-metal on the basis of their chemical properties.

Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).

What happens at the synapse between two neurons?

The gap between two neurons is called a ______.

What is the function of receptors in our body?

Which signals will get disrupted in case of a spinal cord injury?

What is the need for a system of control and coordination in an organism?

Compare and contrast nervous and hormonal mechanisms for control and coordination in animals.