If the atomic number of an atom is 17 and mass number is 35, then number of neutrons will be

1. 35
2. 17
3. 18
4. 52

The number of electrons in an atom is equal to the number of

1. protons in a neutral atom
2. neutrons in a neutral atom
3. nucleons in a neutral atom
4. none of the above

The correct electronic configuration of sodium is:

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

Assertion (A): Matter consists of very small particles called atoms.

Reason (R): Atoms are indivisible.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.