Question

Which of the following has the mass closest in the value to that of the positron:
1. Proton
2. Electron
3. Neutron
4. None of these

Answer 1

Correct Answer - Option 2 : Electron

CONCEPT:

Positron:

• A positron is a positively charged subatomic particle having the same mass and magnitude of charge as the electron.
• Positrons were discovered by Carl David Anderson in cloud-chamber studies of the composition of cosmic rays in 1932.

​EXPLANATION:

• A positron is a positively charged subatomic particle having the same mass and magnitude of charge as the electron.
• Hence, option 2 is correct.

Neutron:

• In 1932, J. Chadwick discovered another subatomic particle that had no charge and a mass nearly equal to that of a proton. It was eventually named a neutron.
• In general, a neutron is represented as ‘n’.
• The mass of a neutron is 1.6750 x 10-27 kg.

Protons:

• A proton is one of three main particles that make up the atom.
• Protons have a positive electrical charge of one (+1) and a mass of 1 atomic mass unit (amu), which is about 1.67×10−27 kilograms.
• Its mass was approximately 2000 times as that of the electron.