http://www.ck12.org Chapter 26. Glossary
26.12 L
laser
Device that produces a very focused beam of light of just one wavelength and color.
law of conservation of charge
Law stating that charges are not destroyed when they are transferred between two materials or within a
material, so the total charge remains the same.
law of conservation of energy
Law stating that energy cannot be created or destroyed in chemical reactions.
law of conservation of mass
Law stating that matter cannot be created or destroyed in chemical reactions.
law of conservation of momentum
Law stating that, when an action and reaction occur, the combined momentum of the objects remains the same.
law of reflection
Law stating that the angle at which reflected rays of light bounce off a surface is equal to the angle at which
the incident rays strike the surface.
law of universal gravitation
Law stating that gravity is a force of attraction between all objects in the universe and that the strength of
gravity is greater when masses of objects are greater or distances between objects are shorter.
lens
Transparent object with one or two curved surfaces that forms images by refracting light.
lever
Simple machine consisting of a bar that rotates around a fixed point called the fulcrum.
lipid
Biochemical compound such as fat or oil that contains oxygen in addition to carbon and hydrogen and is made
up of long carbon chains called fatty acids.
liquid
State of matter that has a fixed volume but not a fixed shape.
longitudinal wave
Wave in which particles of the medium vibrate in the same direction that the wave travels.
loudness
How a listener perceives the intensity of sound.
luminescence
Production of visible light that does not involve high temperatures but instead occurs through chemical
reactions or other means.