| A | B |
|---|
| latent heat | the heat added or removed from a substance that produces a change of phase with no change in temperature |
| latitude | the distance north or south of the equator, measured in degrees |
| light year | the distance light travels in a year |
| liquid | a substance that takes the shape of its container, up to a definite upper surface |
| liter | a unit of volume equal to 1000 cubic centimeters |
| longitude | the distance east or west of the prime meridian, measured in degrees |
| lunar eclipse | condition in which the earth comes between the sun and the moon so that the moon is in the earth's shadow |
| magnet | a device made of a ferromagnetic material, such as steel, which can exert forces on other such materials |
| magnetism | the excess force (above the electrostatic force) exerted on each other by charges in motion |
| mass | the quantity of substance in an object, measured either by its acceleration when a force is applied or by its gravitational attraction to other objects |
| melting | the change of matter from solid to liquid |
| melting point | the temperature at which the solid and liquid phases of a substance can exist in equilibrium |
| menstruation | the monthly process by which the lining of the uterus sloughs off, accompanied by bleeding through the vagina |
| mineral | an earth substance with specified chemical constitution |
| molecule | a particle consisting of one or more atoms bound together, and comprising the smallest quantity of a non-ionic substance |
| muscle | an organ that produces motion of body parts or change in shape of organs by contracting |
