Atoms and Molecules — Science STD 9 — Question

In which of the following conditions, the distance between the molecules of hydrogen gas would increase?

1. Increasing pressure on hydrogen contained in a closed container.
2. Some hydrogen gas leaking out of the container.
3. Increasing the volume of the container of hydrogen gas.
4. Adding more hydrogen gas to the container without increasing the volume of the container.

1. (i) and (ii)
2. (i) and (iv)
3. (ii) and (iii)
4. (ii) and (iv)

Which of the following is true?

Which of the following elements has the same molecular mass as its atomic mass?

1. Nitrogen.
2. Neon.
3. Oxygen.
4. Chlorine.

The atomic number of an element X is 13. What will be the number of electrons in its ion X³⁺?

1. 11
2. 15
3. 16
4. 10

The chemical which can be used to separate a mixture of carbon powder and sulphur powder successfully is:

A few substances are arranged in the increasing order ‘forces of attraction’ between their particles. Which one of the following represents a correct arrangement?

Neon and chlorine have atomic numbers 10 and 17 respectively. Their valencies will be ______ and ______ respectively:

Pure copper sulphate can be obtained form an impure sample by the process of:

Which one of the following set of phenomena would increase on raising the temperature?

1. Diffusion, evaporation, compression of gases.
2. Evaporation, compression of gases, solubility.
3. Evaporation, diffusion, expansion of gases.
4. Evaporation, solubility, diffusion, compression of gases.