Everything is made up of atoms. Each one of them has three particles : protons, neutrons and electrons. Electrons spin around the centre of an atom. They have a negative charge. Protons, which are in the centre of atoms, have a positive charge.
Normally, an atom has as many protons as it has electrons. It is stable or balanced. Carbon, for example has six protons and six electrons.
Scientists can make electrons travel from one atom to another. An atom that loses electrons is positively charged, an atom that gets more electrons is negatively charged.
Electricity is created when electrons move between atoms. Positive atoms look for free negative electrons and attract them, so that they can be balanced.
Parts of an atom