The question asks about J.J. Thomson's model of the atom. We need to recall the key features of this model, particularly how it described the distribution of mass within the atom.
Correct Option: D) Uniformly distributed throughout the atom
The question asks to identify the correct statement about Thomson's model of the atom. We need to recall the key postulates of Thomson's atomic model and compare them with the given options.
Correct Option: C) The positive and negative charges in an atom are equal in magnitude, making it electrically neutral. This is a core postulate of Thomson's atomic model, which aimed to explain the overall electrical neutrality of atoms.
The question asks about the specific metal used as a thin sheet in Rutherford's alpha-particle scattering experiment. This is a direct recall question related to a foundational experiment in atomic physics.
D) Gold was the metal used in Rutherford's alpha-particle scattering experiment due to its extreme malleability, allowing it to be made into a very thin foil, and its high atomic mass, which provided a strong positive charge for scattering alpha particles.
Rutherford's alpha-particle scattering experiment was a landmark experiment that led to the nuclear model of the atom. The key observations from this experiment provided crucial insights into the structure of the atom. We need to analyze the observation that most alpha particles passed straight through the gold foil to deduce its implication about atomic structure.
C) Most of the space inside the atom is empty. This directly follows from the observation that the vast majority of alpha particles passed undeflected through the gold foil. If atoms were solid, this would not have been possible.
Rutherford's alpha-scattering experiment was a landmark experiment that led to the discovery of the atomic nucleus. By observing how alpha particles interacted with a thin gold foil, Rutherford and his team deduced key properties about the structure of the atom. The crucial observation of a very small fraction of alpha particles bouncing back at nearly 180° provided direct evidence for a concentrated, positively charged mass within the atom.
B) All the positive charge and most of the mass of the atom were concentrated in a very small volume — This statement accurately reflects Rutherford's conclusion based on the observation of alpha particles bouncing back at nearly 180°. The strong electrostatic repulsion required to reverse the path of a fast-moving alpha particle could only come from a highly concentrated positive charge and mass.
This question asks about the results of Rutherford's alpha-particle scattering experiment, specifically the proportion of alpha particles that were deflected by a large angle (nearly 180°). This experiment led to the discovery of the atomic nucleus.
C) 1 — This is the correct number, as approximately 1 out of every 12,000 alpha particles was observed to be deflected by nearly 180°.