Question

How many subatomic particles are present in an a-particle used in Rutherford’s scattering experiment?
A. No. of Protons - 4
No. of neutrons - 0
No. of Electrons – 0
B. No. of Protons - 2
No. of neutrons - 0
No. of Electrons – 2
C. No. of Protons - 2
No. of neutrons - 2
No. of Electrons – 0
D. No. of Protons - 2
No. of neutrons - 2
No. of Electrons – 1

Answer 1

Hint: In the start, Dalton gave us the postulates that state that the atom is the basic unit of matter and that atom cannot be divided any further. With the advancement of technology, we came to know that the atom is made up of several subatomic particles. The nature of these particles was not known at that time and needed to be discovered so many scientists did a series of experiments on the atoms to uncover their secrets.

Complete step by step answer:
When it was found out that atoms are formed up of various subatomic particles, various scientists from all around the world carried on experiments of different types to gather more and more information about the nature of these subatomic particles.
One of the experiments was the Rutherford scattering experiment in which Rutherford used a gold film to gain the results. He used a beam to bombard the thin gold film with alpha particles. It was found out that the particles followed different paths when they approached different places of the metalcore.
Some of the particles moved undivided while some were completely bounced back.
The alpha particles used in the experiment is the doubly charged helium ions, which means that when the helium is ionised by 2 electrons then they form alpha particle so since the atomic number of helium ions is 2 being ionised with 2 electrons results with 9 electrons s

So, the correct answer is C.

Note: Gold was used as the metal in Rutherford's scattering experiment because gold is a highly malleable metal which means it can be beaten into very thin sheets and thus can be used in the experiment since the experiment required the sheet which is only as thick as one atom.