The smallest particle of matter which may or may not have independent existence is :

1. Molecule
2. Atom
3. Radical
4. Element

The number of atoms of the same type which combine to form a molecule of an element is called its :

1. Atomicity
2. Valency
3. Molecular formula
4. Compound

The number of atoms present in a molecule of water is:

1. 2
2. 3
3. 4
4. 5

What does 2H represent ?

1. two atoms of hydrogen
2. two molecules of hydrogen
3. one molecule of hydrogen
4. none of the above