The Fundamental Unit of Life — Science STD 9 — Question

There are four elements P, Q, R and S having atomic numbers of 4, 18, 10 and 16 respectively. The element which can exhibit covalency as well as electrovalency will be:

1. P.
2. Q.
3. R.
4. S.

Herdmania is a:

1. Urochordate.
2. Cephalochordate.
3. Hemichordate.
4. Craniate.

The master mind of the cell is:

A freely falling object eventually stops on reaching ground. What happens to its potential and kinetic energy while falling?

Inland fisheries is referred to:

1. Culturing fish in freshwater.
2. Trapping and capturing fishes from sea coast.
3. Colchicine treatment.
4. Breeding with their wild relatives.

The principal cereal crop of India is:

1. Wheat
2. Rice
3. Maize
4. Sorghum

It is an ionic compound:

In water, the proportion of oxygen and hydrogen by mass is:

Which of the following represents the correct electron distribution in magnesium ion?

1. 2, 8
2. 2, 8, 1
3. 2, 8, 8
4. 2, 8, 7

Which among the following is a wrong differentiation between mass and weight ?