In solar cells, solar radiation boosts electrons to higher energy states, thereby releasing them from their atomic bonds as electricity begins to flow. Scientists have now developed a novel method to ...

Key learning points Electrical charges What are free electrons? Cell polarity Conventional current direction Electrons orbit the nucleus. An atom has a neutral charge, because it contains the same ...

Listen to the full series on BBC Sounds. Charge is a property of a body which experiences a force in an electric field. Charge is measured in coulombs (C). Since electrons are so small and one ...