Inside the atom  

Protons and neutrons make up the nucleus of an atom.

Electrons move about in the space around the nucleus.

• A proton has a positive charge

• An electron has a negative charge

• A neutron has no charge

An uncharged atom has equal numbers of protons and electrons.

• Adding electrons makes an atom negative

• Losing electrons makes an atom positive

Charging by friction

When some insulators are rubbed together, the friction causes the electrons to be scraped off one insulator and transferred onto the other, giving one a positive charge and the other an equal negative charge

• Rubbing a polythene rod with a dry cloth transfers electrons to the surface atoms of the rod from the cloth. The polythene rod becomes negatively charged

• Rubbing an…