Video Transcript
James Chadwick proved the existence of blank. (A) The quantum atomic model, (B) the electron cloud model, (C) the electron, (D) the neutron, or (E) the proton.
Experiments conducted by James Chadwick helped advance the understanding of atomic structure. In his experiment, a sample of beryllium was bombarded with positively charged 𝛼 particles. This resulted in the beryllium emitting high-energy unknown radiation, which was then directed at paraffin wax. This caused the wax to emit protons, which were counted using a detector. This unknown radiation was high energy and neutral and was found to have a mass about the same as a proton. This led to the conclusion that a neutral particle is present in the atom called the neutron. This discovery was incredibly important as it explained the existence of isotopes, which are atoms of the same element with the same number of protons but a different number of neutrons.
Therefore, James Chadwick proved the existence of answer choice (D) the neutron.
