Answer : 2. "Ernest Rutherford "
Explanation :

1. The proton was discovered by Rutherford. The name proton is derived from the Greek word protos meaning 'first'. The proton is a positively charged particle located in the nucleus of an atom, which was discovered by Ernest Rutherford in 1920. Rutherford proved in 1917 that the nucleus of the hydrogen atom (ie a proton) is present in the nuclei of all other atoms.

2. The nucleus of the atom was discovered by Ernest Rutherford in his famous gold foil experiment in the year 1911. The value of the particle is 1.6*10-19 C. To make an atom neutral, it has the same number of protons and electrons. He used the same concept to discover the proton.