Question

How is it possible for one electrically neutral atom to exert an electrostatic force on another electrically neutral atom?

Short answer

Answer: An electrically neutral atom can exert an electrostatic force on another electrically neutral atom due to the momentary and local charge imbalances caused by the redistribution of electron densities when the atoms get close to each other. This redistribution results in the formation of temporary dipoles, which allows for attractive and repulsive electrostatic forces to come into play between the atoms, despite their overall neutral charge.

Step-by-step solution

1. Atomic Structure: Understanding Electrically Neutral Atoms

An electrically neutral atom consists of an equal number of positively charged protons in the nucleus and negatively charged electrons surrounding the nucleus. The positive charge of protons and the negative charge of electrons cancel each other out, resulting in an overall neutral charge.

2. Concept of Electrostatic Force

Electrostatic force is the force between charged particles, either protons or electrons. It can be attractive or repulsive, depending on the types of charges involved. According to Coulomb's law, the electrostatic force (F) between two charges (q1 and q2) is directly proportional to the product of their charges and inversely proportional to the square of the distance (r) between them: F = k * (q1*q2)/r^2, where k is the electrostatic constant.

3. Redistribution of Charges Between Atoms

When two electrically neutral atoms get close to each other, the electron cloud of each atom influences the other. The negatively charged electrons in one atom can repel the electrons in the other atom, causing the electron clouds to shift slightly. This redistribution of electron density results in one side of each atom being momentarily more negative (due to higher electron density), while the other side becomes more positive (due to lower electron density). This phenomenon is known as a temporary dipole.

4. Electrostatic Force Between Electrically Neutral Atoms

With the formation of temporary dipoles in the atoms, there is a net charge imbalance within each atom. This charge imbalance allows for the electrostatic force to come into play between the atoms, despite them being overall electrically neutral. The electrostatic force between the positive side of one atom and the negative side of another atom can cause attraction, while the interaction between the same charge types can cause repulsion. This way, an electrically neutral atom can exert an electrostatic force on another electrically neutral atom due to the momentary and local charge imbalances caused by the redistribution of electron densities.