# Charge Model

Photoelectric Effect

### Introduction

When rods of plastics are placed next to each other, nothing really happens. However, when we rub rods of plastic with materials such as wool or silk, we notice that forces are somehow exerted between them. This is the Triboelectric Effect.

We call these objects charged, as they have the ability to exert forces on each other.

From this definition of a charged object, it may be difficult to differentiate a neutral object from a charged object. We say that an important characteristic of any charged object is that it can pick up small pieces of paper.

Let us define the properties of our Charge Model, that we have determined from the experiment:

1. Friction Force add charge or remove it from the object. The process is called charging.
2. There are two types of charges, positive and negative. Charges of the same sign exert repulsive forces on each other, while charges of opposite signs attract each other.
3. The force between charges depends on the distance and the quantity of charge. The shorter the distance, the greater the force. The greater the number of charges, the greater the force.
4. There are two types of materials, conductors and insulators. Charges easily move through conductors, while insulators are where materials remain fixed in place.
5. Charges can be transferred to each other by contact.

### Quantifying the Electric Charge

We take a look at the structure of an Atom.