Question

$\alpha$-ray scattering experiment proved that positive particles are present in the extranuclear part of an atom.

• A. True
• B. False

Answer 1

The correct option is B False

1. $\alpha$-ray scattering experiment: In this experiment, Rutherford bombarded a thin sheet of gold foil with alpha particles and studied the deflection caused to alpha particles by placing a zinc sulfide screen around the gold foil. He observed that:

1. Most of the alpha particles passed through the gold foil sheet without any deflection.
2. Some of the alpha particles got deviated by a small angle.
3. Very few alpha particles got deflected back by 180^° angle.

2. Postulates:

1. The space in an atom is mostly empty.
2. The positive charge and the mass of the atoms are concentrated in a very small volume. He termed this region, the nucleus.
3. Negatively charged electrons move around the nucleus in circular orbits.
4. As the nucleus is positively charged and the electrons are negatively charged, they are held together in an atom by electrostatic forces.

3. Hence, positive particles are present in the nucleus and not in the extranuclear part of an atom. Electrons are present in the extranuclear part of an atom.

Therefore, the given statement is FALSE.