Black body - a theoretical body that reflects none of the radiation incident on it and so absorbs all of it

Blue-shift - an decrease in the observed wavelength

Boiling - the change from the liquid to the vapour state at a specific constant temperature

Bottom - a flavour of quark with electric charge but heavier than the strange quark

Boyle’s law - the relation between pressure and volume of a fixed quantity of an ideal gas when the temperature is kept constant

Capacitance - the charge that can be stored on a capacitor per unit voltage

Capacitor - a device that can store electric charge

Carbon brushes - conducting, soft material that joins the slip rings to the external circuit in an ac generator

Centripetal acceleration - the acceleration due to a changing direction of velocity

Centripetal force - a force pointing to the centre of a circular path