Almost the entire mass of an atom is concentrated in
Almost the entire mass of an atom is concentrated in
The correct option is D Nucleus
Explanation for correct option
(D) Rutherford discovered the nucleus in an atom by a gold foil experiment. The atomic mass of the atom is the sum of the total number of protons and neutrons present in the nucleus.
Explanation for incorrect option
(A) Total number of protons present in the nucleus is equal to the atomic number of that element. Only protons do not decide the mass of the atom.
(B) Electrons are present outside the nucleus and revolve around the nucleus in a fixed energy path known as orbits.
(C) Neutrons are present in the nucleus and along with protons they make total mass. Neutrons cannot form the total mass of the nucleus.
Thus, the total mass is decided by the sum of protons and neutrons present in the nucleus of the atom.
Therefore, option (D) nucleus is the correct answer.
Nucleus
Explanation for correct option
(D) Rutherford discovered the nucleus in an atom by a gold foil experiment. The atomic mass of the atom is the sum of the total number of protons and neutrons present in the nucleus.
Explanation for incorrect option
(A) Total number of protons present in the nucleus is equal to the atomic number of that element. Only protons do not decide the mass of the atom.
(B) Electrons are present outside the nucleus and revolve around the nucleus in a fixed energy path known as orbits.
(C) Neutrons are present in the nucleus and along with protons they make total mass. Neutrons cannot form the total mass of the nucleus.
Thus, the total mass is decided by the sum of protons and neutrons present in the nucleus of the atom.
Therefore, option (D) nucleus is the correct answer.
