Here's why:

* Electrostatic Force: Charged particles create an electric field around them. This field exerts a force on other charged particles.

* Like Charges Repel: The force between two particles with the same charge (both positive or both negative) is repulsive. This means they push each other away.

* Opposite Charges Attract: Conversely, the force between two particles with opposite charges (one positive and one negative) is attractive. They pull each other closer.

Analogy: Imagine two magnets with the same pole facing each other (north-north or south-south). They will push each other apart.

Examples:

* Static Electricity: When you rub a balloon on your hair, electrons transfer, making the balloon negatively charged. The balloon then repels other negatively charged objects, like your hair, making it stand on end.

* Atomic Structure: Protons within the nucleus of an atom repel each other due to their positive charges. The strong nuclear force overcomes this repulsion, holding the nucleus together.

Let me know if you'd like more details on any of these concepts!