Question

Which of the following forces bind electrons to nuclei to form atoms: strong force, contact force, electromagnetic force, gravitational force?

Short answer

Answer: Electromagnetic force.

Step-by-step solution

Identify the relevant forces at the atomic level.

At the atomic level, the strong force, electromagnetic force, and gravitational force are relevant forces that could be responsible for binding electrons to the nucleus. The contact force is not relevant since it is a macroscopic force and doesn't act at atomic levels.

Analyze the strong force.

The strong force, also known as the strong nuclear force, is a fundamental force that binds protons and neutrons in the nucleus of an atom. The strong force is not responsible for holding electrons in the atom, as its influence extends only a very short distance from the nucleus and doesn't have an attractive effect on the electrons.

Analyze the electromagnetic force.

The electromagnetic force is another fundamental force in nature that acts between electrically charged particles. In an atom, the positively charged protons in the nucleus and the negatively charged electrons experience an attractive electromagnetic force. This force is responsible for holding electrons in their orbits around the nucleus, forming an atom.

Analyze the gravitational force.

Gravitational force is the attractive force between masses. Although protons and electrons in an atom have mass and do experience a gravitational force, this force is extremely weak compared to the electromagnetic force. At atomic scales, gravity has negligible influence on the behavior of electrons around the nucleus.

Select the correct force.

The force responsible for binding electrons to nuclei to form atoms is the electromagnetic force. This is because the electromagnetic force is the attractive force between the positively charged protons in the nucleus and the negatively charged electrons, holding them in orbit around the nucleus. The other forces, either do not act on electrons at the atomic level or are too weak to have a significant effect.