Hadrons– elementary particles that take part in nuclear interactions through the strong nuclear force (see table 32.1)

Half-life – the time required for the decay of one-half the unstable atoms initially present (see Table 26.3)

Hall effect - The occurence of a voltage developed across a conductor placed in a magnetic field.

Harmonic frequencies – resonant frequencies that are integer multiples of the fundamental frequency of an object

Harmonic wave– a wave generated by a simple harmonic motion

Heat – energy which is transferred due solely to a temperature difference

Heat capacity – amount of thermal energy required to change an objects temperature by 1°

Heat of fusion – the energy required to change a unit mass of a substance from a solid to a liquid (or the energy given up when a unit mass changes from a liquid to a solid)

Heat pump – a system that takes heat from a cooler outside and delivers that heat to a warmer inside

Heat of transformation – for a change of phase, the ratio of the amount of heat absorbed (or released) to the mass of material undergoing the phase change (see equation 11.8)

Heat of vaporization – the energy required to change a unit mass of a substance from a liquid to a gas (or the energy given up when a unit mass changes from a gas to a liquid)

Henry – unit of measurement of inductance, equal to 1 volt-second per ampere

Hertz – the SI unit of frequency, abbreviated Hz

Hologram – photographic recording of the interference pattern produced by a combination of reference and object beams resulting in the formation of an image without the use of a lens

Holography – the making of and study of holograms (see definition of hologram)

Hooke’s law – the force exerted by a deformed elastic medium (like a spring) is proportional to the deformation and in the opposite direction of the deformation

Huygen's principle – each point on a wave front can be considered as the source of a new wave

Hyperons – atomic particles, with a mass of about 1000 times that of an electron, whose decay products always include a proton