What concept did Ernest Rutherford's gold foil experiment reveal?

What concept did Ernest Rutherford's gold foil experiment reveal?

• A. The mass of an atom is evenly distributed
• B. The existence of a dense, positively charged nucleus
• C. Electrons orbit the nucleus at fixed distances
• D. Atoms are entirely empty space

Answer: (B)

Ernest Rutherford's gold foil experiment was pivotal in understanding atomic structure. The experiment involved directing a stream of alpha particles at a thin sheet of gold foil. Most of the alpha particles passed straight through the foil, suggesting that atoms are largely empty space. However, a small number were deflected at large angles, while a very few even bounced back toward the source. This observation led Rutherford to conclude that there must be a very small, dense region within the atom that contains most of its mass and is positively charged, as it repelled the positively charged alpha particles. This region is what we now call the nucleus. The experiment disproved the earlier plum pudding model, which suggested that positive charge was spread out evenly throughout the atom. Instead, Rutherford demonstrated that the nucleus is at the center, containing protons and, as we later learned, neutrons. Therefore, the discovery of the dense, positively charged nucleus was a groundbreaking development that reshaped the understanding of atomic structure.

Ernest Rutherford's gold foil experiment was pivotal in understanding atomic structure. The experiment involved directing a stream of alpha particles at a thin sheet of gold foil. Most of the alpha particles passed straight through the foil, suggesting that atoms are largely empty space. However, a small number were deflected at large angles, while a very few even bounced back toward the source.

This observation led Rutherford to conclude that there must be a very small, dense region within the atom that contains most of its mass and is positively charged, as it repelled the positively charged alpha particles. This region is what we now call the nucleus. The experiment disproved the earlier plum pudding model, which suggested that positive charge was spread out evenly throughout the atom. Instead, Rutherford demonstrated that the nucleus is at the center, containing protons and, as we later learned, neutrons.

Therefore, the discovery of the dense, positively charged nucleus was a groundbreaking development that reshaped the understanding of atomic structure.