Electricity is everywhere,thanks to the unique structure of the universe.Matter,which is basically everything you see and touch,is made up of tiny units called atoms.Atoms themselves are made up of even tinier parts called protons and neutrons,which form the atom's core,and electrons,which move around outside the core.

    Protons have a positive electrical charge,and electrons have a negative electrical charge.Normally,an atom has an equal number of electrons and protons.The positive and negative charges cancel each other out,so the atom is neutral.

    When an atom gains an extra electron, it becomes negatively charged.When an atom loses an electron,it becomes positively charged.When the conditions are right,such charge imbalances can generate a current of electrons.This flow of electrons (or electrically charged particles) is what we call electricity.

    The first person to discover that electricity plays a role in animals was Luigi Galvani, who lived in Italy in the late 18th century.He found that electricity can cause a dissected frog's leg to twitch,showing a connection between electrical currents traveling along an animal's nerve and the action of muscles.