Structure of the Atom — Science STD 9 — Question

Name the three subatomic particles present in an atom.

Name two viral diseases of the cattle.

Which of the Kepler’s laws of planetary motion led Newton to establish the inverse-square rule for gravitational force between two bodies?

Arrange these statements in correct sequence of preparation of green manure.
Plants are ploughed and mixed into the soil.

Group the following and tabulate them as energy yielding, protein yielding, oil yielding and fodder crop.
Wheat, rice, berseem, maize, gram, oat, pigeon gram, sudan grass, lentil, soyabean, groundnut, castor and mustard.

What type of motion is exhibited by a freely falling body?

 Explain why, if a stone held in our hand is released, it falls towards the earth.