Ohio Assessment for Educators (OAE) Integrated Science (024) Practice Exam

In the Gold Foil Experiment conducted by Ernest Rutherford, alpha particles were directed at a thin foil of gold. The experiment revealed that most of the alpha particles passed straight through the foil, but some were deflected at large angles, and a few even bounced back. This observation was pivotal in leading to the conclusion that atoms consist of a small, dense, positively charged nucleus.

The deflection of the alpha particles was primarily due to their interaction with the positively charged nucleus of the gold atoms. The nucleus, which contains protons, exerts a strong electric force on the positively charged alpha particles. When an alpha particle comes close to the nucleus, the repulsion experienced due to the like charges can cause the particle to be deflected. This was a groundbreaking finding at the time, as it contradicted the then-accepted plum pudding model of atomic structure and led to the modern understanding of atomic structure, where the nucleus plays a central role.

This understanding of atomic nuclei and how they interact with charged particles is foundational in fields such as nuclear physics and chemistry.