What do you think would happen if α-particles were replaced with negatively charged particles in Rutherford’s gold foil experiment?
If negatively charged particles were used instead of α-particles, most of them would still pass through the gold foil undeflected because most of the atom is empty space.
However, the deflection pattern would change significantly. Since the nucleus contains all the positive charge of the atom, the negatively charged particles would be attracted towards the nucleus rather than repelled. Unlike α-particles, which bounced back due to repulsion from the positive nucleus, negatively charged particles would not bounce back. Instead, particles passing near the nucleus would be deflected towards it due to the attractive force between opposite charges, making it difficult to detect the presence of a small, dense, positively charged nucleus.
Explanation
The textbook context establishes that α-particles are positively charged and were deflected/bounced back due to repulsion from the positively charged nucleus. If negatively charged particles were used, the fundamental interaction with the nucleus would change from repulsion to attraction. While most particles would still pass through the empty space of the atom, those approaching the nucleus would be pulled toward it rather than pushed away. This means no particles would bounce back, and the scattering pattern would differ, making it harder to deduce that positive charge is concentrated in a tiny central nucleus.
Solution Steps
Step 1: Identify that α-particles are positively charged and the nucleus contains all positive charge
Step 2: Recognize that like charges repel (α-particles repelled by nucleus) and opposite charges attract
Step 3: Conclude that negatively charged particles would be attracted to the positive nucleus rather than repelled
Step 4: State that most particles would still pass through (empty space) but deflection would be toward the nucleus, not away from it, and no bouncing back would occur