All things we use are made up of elements, and each element is made up of atoms. Movement of electrons in a material constitutes electric current and generates an energy called electric energy or electricity.
1. The Atom
- John Dalton considered that atoms cannot be divided further.
- Later, Rutherford's gold foil experiment showed that atoms are made up of particles like proton, electron and neutron – the sub-atomic particles.
- Proton and neutron are found inside the nucleus, at the centre of the atom. Electrons revolve around the nucleus in different paths called orbits.
- In an atom, the number of protons and the number of electrons are equal.
- There is a force of attraction between the protons in the nucleus and the electrons in the orbits. Electrons in the inner orbits are strongly attracted and cannot be removed easily; electrons in the outermost orbits are loosely bound and can be easily removed.