P-2 Animal Classification — Science STD 10 — Question

Write in brief about progressive changes in animal classification?

Write short notes: Connecting link.

Observe the following diagram and answer the questions given below:


i. Identify the above diagram.
ii. Write the principle on which the above appliance works.
iii. write the working of the above appliance.
iv. Write the use of the above appliance.

What is esterification and give its uses?

An element A which is a part of common salt and kept under kerosene reacts with another element B of atomic number 17 to give a product C. When an aqueous solution of product C is electrolysed then a compound D is formed and two gases are liberated.

1. What are A and B?
2. Identify C and D.
3. What will be the action of C on litmus solution? Why?
4. State whether element B is a solid, liquid or gas at room temperature.
5. Write formula of the compound formed when element B reacts with an element E having atomic number 5.

Write short note :
Transition Elements.

Explain why the value of g is zero at the centre of the earth

Why is it beneficial to use a satellite j launch vehicle made up of more than one stage?

The metal M reacts vigorously with water to form a solution S and a gas G. The solution S turns red litmus to blue whereas gas G, which is lighter than air, burns with a pop sound. Metal M has a low melting point and it is used as a coolant in nuclear reactors.

1. What is metal M?
2. What is solution S? Is it acidic or alkaline?
3. What is gas G?
4. Write a balanced chemical equation for the reaction which takes place when metal M reacts with water.
5. Is this reaction exothermic or endothermic?

Explain the following terms with example: Unsaturated hydrocarbons.