Question

What is a positively charged core in the center of the atom is called?

• A. Neutron
• B. Anode
• C. Proton
• D. Nucleus

Answer 1

The correct option is D

Nucleus

The explanation for the correct option

Option D

• From the alpha scattering experiment Rutherford's proposed that an atom consists of a small positively charged nucleus that is situated at the center of the atom.
• The entire mass and charge of the atom are concentrated at this center.
• Size of the nucleus is very very small as compared to the size of the atom.

The explanation for the incorrect answer

Option A

• The scientist James Chadwick, bombarded alpha radiation from a polonium source into a sheet of Beryllium ($\mathrm{Be}$).
• This resulting penetration does not carry any charge but their mass is equal to that of protons.
• They are named as neutrons.
• Neutrons are represented by the letter “n”.

Option B

• In 1879, the scientist William Crookes invented an experimental glass tube with a partial vacuum known as a discharge tube.
• In that tube, he inserts 2 metal plates called electrodes at each of the ends.
• The electrode which is connected to the positive terminal of the voltage source is called the anode.
• The rays emitted from the anode are positively charged and they are called anode rays.

Option C

• E.Goldstein discovered the positively charged particle by using a discharge tube filled with $\mathrm{Hydrogen}\left(\mathrm{H}\right)$.
• These positively charged particles have a charge equal to and opposite to that of electrons. Hence they are called protons.
• The protons are represented by the letter "P".

Thus, option D i.e., the nucleus is correct.