While catching a cricket ball the fielder lowers his hands backwards. Why?

What will be the frequency sound having 0.20 m as its wavelength, when it travels with a speed of 331 m s^–1?

Give the SI unit of radioactivity

What is Molar volume of a gas?

What is rust? (or) How is rust formed? Give the equation for formation of rust.

A hot saturated solution of copper sulphate forms crystals as it cools. Why?

Define combination reaction. Give one example for an exothermic combination reaction.

How do detergents cause water pollution? Suggest remedial measures to prevent this pollution?

What is the common step in aerobic and anaerobic pathway?

Why is the teeth of rabbit called heterodont?

Name the heart valve associated with the major arteries leaving the ventricles.

What are transgenic organisms?

What is metastasis?

Solar energy is a renewable energy. How?

What is Stage?