Question

Proton was discovered by
   (A) Thomson
   (B) Rutherford
   (C) Chadwick
   (D) Goldstein

Answer 1

Hint: The scientist who discovered proton is also the man behind the gold foil experiment. He's also known as the father of nuclear physics. He was awarded the Nobel prize in chemistry in 1908.

Complete answer:
-As we know proton is a subatomic particle, with a positive electric charge and a mass slightly less than that of the neutron.
-The number of protons in the nucleus acts as the defining property of an element, and is referred to as the atomic number. It's represented by the symbol Z.
-We often refer the term proton to the hydrogen ion, ${{H}^{+}}$.Its because since the atomic number of hydrogen is 1 and when an electron is lost it only contain a proton.
 - There are mainly three scientists associated with the discovery of the proton. First one is English chemist William Prout who suggested that all atoms are made up of hydrogen atoms in 1815 and he referred to them as protyles.
-The second scientist is the German physicist Eugen Goldstein. He discovered canal rays (positively charged ions formed by gases) in1886. He observed that the charge-to-mass ratio of the hydrogen ion was the highest among all gases. He also observed that the hydrogen ion had the smallest size among all ionized gases.
- The third scientist is Ernest Rutherford. He discovered the nucleus of the atom in the year 1911 by his famous gold foil experiment. Rutherford concluded that all the positively charged particles in an atom were concentrated in a singular core and that most of the atom’s volume was empty. Rutherford stated that the total number of positively charged particles in the nucleus is equal to the total number of negatively charged electrons present around it.
-The discovery of the proton is credited to Ernest Rutherford, who proved that the nucleus of the hydrogen atom (a proton) is present in the nuclei of all other atoms in the year 1917.

Therefore, the answer is option (B) Rutherford.

Note:
A confusion may occur among the options. So, it's good to remember about discoveries of other fundamental particles too. Thomson discovered electrons in 1897, Chadwick discovered neutrons in 1932 and Goldstein discovered canal ray in 1886.