Question

Ernest Rutherford performed an experiment in which he shot alpha particles through a thin layer of gold foil. He predicted that the alpha particles would travel straight through the gold atoms, as shown below. 163x119 However, Rutherford observed that although most of the alpha particles passed straight through the foil, a few alpha particles were deflected, as shown below. 163x118

Which of the following statements about the atom did Rutherford’s experiment support?

A) An atom contains protons, neutrons, and electrons.
B) An atom’s nucleus is small and has a positive charge.
C) Electrons follow a predictable path around the nucleus.
D) Different isotopes of an element have different masses.

Answer 1

Rutherford's experiment supported the statement that an atom's nucleus is small and positively charged. This finding contradicted the plum pudding model and led to the establishment of the nuclear model of the atom. The small number of alpha particles that were deflected evidenced a dense, positive center in atoms.

Step-by-step explanation:

Ernest Rutherford's Gold Foil Experiment

The question pertains to the gold foil experiment conducted by Ernest Rutherford which revolutionized the understanding of atomic structure. Alpha particles, which are helium atoms without electrons, were expected to pass through the gold foil with minimal deflection according to the plum pudding model. Instead, Rutherford observed that while most alpha particles did pass through as predicted, a small fraction were deflected at large angles, and some were even scattered back towards the source. This observation was incompatible with the then-current atomic model and led to a groundbreaking conclusion.

Rutherford's experiment supported the statement that an atom’s nucleus is small and has a positive charge. This was evidenced by the unexpected deflection of the alpha particles, which indicated the presence of a dense, positively charged center within the atom. The fact that most alpha particles passed through the foil with little interference suggested that the atom is mostly empty space, and the occasional dramatic deflection showed that when alpha particles encountered the dense nucleus, they were repelled by the positive charge.

The nuclear model of the atom emerged from these observations, proposing that nearly all the mass of an atom and its positive charge are concentrated in a central nucleus, around which electrons move in the remaining vast space.