Physics – 5.1.1 The atom | e-Consult

The positive charge of the nucleus is evidenced by the electrostatic repulsion between the positively charged alpha particles and the positively charged protons within the nucleus. As alpha particles approach the nucleus, they experience a strong electrostatic force that causes them to deflect. The direction and magnitude of the deflection are directly related to the strength of the electrostatic force. The fact that the alpha particles are deflected, and often change direction significantly, indicates that they are interacting with a positive charge. This repulsion is consistent with the model of a positively charged nucleus.

• The deflection of alpha particles demonstrates the presence of a repulsive electrostatic force.
• The direction of deflection is away from the nucleus, indicating a positive charge.
• The energy loss of alpha particles upon interaction is due to the electrostatic interactions.