When two objects are rubbed together, electrons can be transferred from one object to the other. This can create a positive charge on one object and a negative charge on the other. The amount of charge that is transferred depends on the materials of the objects and the amount of friction that is applied.

Some materials are more likely to lose electrons than others. For example, metals are more likely to lose electrons than non-metals. This is because the electrons in metals are more loosely bound to the atoms than the electrons in non-metals.

The amount of friction that is applied also affects the amount of charge that is transferred. The more friction that is applied, the more electrons will be transferred.

Stretching

When an object is stretched, the distance between the atoms in the object increases. This can cause the electrons in the object to move closer together. This can create a positive charge on the object.

The amount of charge that is created depends on the amount of stretching that is applied. The more the object is stretched, the more positive the charge will be.

Examples

Some examples of objects that can be charged by friction include:

* A balloon rubbed against hair

* A piece of cloth rubbed against a plastic comb

* A rubber rod rubbed against a glass rod

Some examples of objects that can be charged by stretching include:

* A rubber band stretched between two fingers

* A piece of plastic wrap stretched over a frame

* A balloon inflated with air