1.Bioluminescence: Light produced by organisms.
2.Light Ray:a straight-line beam of light as it travels outward from its source.
3.Law of reflection:the angle of an incoming light ray equals the angle of the reflected ray.
4.Concave Mirror:a mirror that curves in on a shiny side.
5.Convex Mirror:a mirror that curves out on a shiny side.
6.Opaque:completely blocking light from passing through.
7.Transparent:letting all light through, so that objects on the other side can be seen clearly.
8.Translucent:letting only some light through, so that objects on the other side appear blurry.
9.Polarization:allowing light vibratioins to pass through in only one direction.
10.Refraction:the bending of the light rays as they pass from one substance into another.
11.Convex Lens:a lens that curves outward (is thicker at the middle than at edges) and brings light rays together.
12.Concave Lens:a lens that curves inward (is thicker at the edges than at the middle) and spreads light rays apart.
13.Prism: A cut piece of clear glass (or plastic) with 2 opposite sides in the shape of a triangle or other geometric shape.
14:spectrum: a band of colors produced when light goes through a prism.
15.Primary color: red,green,or blue;mixing these colors can produce all the colors of the spectrum.
16.Primary pigment: magenta,cyan,yellow;material with any of this colors absorb one primary color of light and reflects the other two.
17.electromagnetism: the production of magnetism by electricity and the preduction of electricity by magnets.
18.electromagnetic spectrum: all the wavelenghts of visible and invisible light in order rom short (gamma rays) to long (radio).
19.laser: a device that produces a thin stream of light of just a few close wavelenghts.
20.Mass: the amount of matter in an object.
21.volume: the amount of space an object takes up.
22.weight: (on Earth) a measure of the force of gravity between Earth and an object.
23.Density: a measure of how tightly packed matter is;the amount of mass contained in a given volume.
24.Buoyancy: the upward push on an object by the liquid (or gas) the object is placed in.
25.Conduct: allow heat or electricity to flow through readily.
26.insulate: no allow heat or elctricity to flow through readily.
27.Element: a basic building block of matter;a pure substance that cannot be broken down into anything simpler.
28.Compund: a chemical combination of two or moree elements into a single substance.
29.Atom: The smallest unit of an element that still has the properties of the element.
30.Proton: a particle with a positive charge in the nucleous of an atom.
31.Neutron:an uncharged particle in the nucleous of an atom.
32.Electron: a particle with a negative charge moving around the nuclous of an atom.
33.Nucleus: The dense center part of an atom.
34.Molecule: A group of more than one atom joined together that acts like a single particle.
35.State of Matter: any of the forms matter can exist in.
36.Melting Point: the temperature at which a solid changes state into a gas.
37.Boiling Point: the temperature at which a liquid changes state into a gas.
38.Freezing Point: the temperature at which a liquid changes tate into solid.
39.Mixture; two or more parts blended together yet keeping their own properties and not turning into a new substance.
40.Solution: a mixture in which substances are completely blended so that the properties are the same throughout and the substances stay blended.
41.Suspension:a mixture of substances that separate upon standing.
42.Colloid: particles (or droplets) large enough to block out light spread throughout another substance.
43.Emulsion: a liquid spread through another liquid.
44.Aerosol: liquid drops or solid particles spread through a gas.
45.Gel: a solid spread through a liquid.
46.Foam: a gas spread through a liquid or solid.
47.Physical Change: a change in size,shape,or state,without forming a new substance.
48.Chemical Change: a change in matter that produces a new substance with different properties from the original.
49.Chemical reaction: a chemical change of original substances before a chemicalreaction takes place.
50.Product: one of the new substances produced when a chemical reaction takes place.
51.Kinetic energy: the energy of a moving object.
52.Potential energy: energy stored in an object or material.
53.Conduction: movement of energy from a hot object that comes into contact with a cooler object;the material remains in place.
54.Convection: movement of energy by the flow of matter from place to place.
55.Radiation: movement of energy in the form of waves that can travel through empty space.
56.Wet cell battery: a battery containing liquid solution that produces the electric current.
57.Dry cell battery: a battery that uses ¨dry chemicals¨ to produce an electric current.
58.Solar system: the Sun and the objects that are traveling around it.
59.Planet: any of the eight large bodies that travel around the sun and shine by reflecting its light.
60.Gravity: a force of attraction,or pull,between any object and any other objects around it .
61.Inertia: The tendency of a moving object to keep moving in a straight line.
62.lithosphere:the hard,outer layer of Earth,about 100 kilometers thick.
63.Crust: the rocky surfacethat makes up the top of the lithosphere.
64.Resource: any material that helps support life on Earth.
65.Hydrosphere: Earth´s water.
66.Fault: a crack in the crust, whose sides show evidence of motion.
67.Geologist: a scientist who studies Earth.
68.Magma: hot,molten rock deep below Earth´s surface.
69.Lava: magma that reaches Earth´s surface.
70.Weathering: the breaking down of rocks into smaller pieces.
71.Erosion: the picking up and carrying away of pieces of rock.
72. Deposition: the droping off of bits of eroded rock.
73.Meteorite: a chunk of rock from space that strikes a surface (such as Earth or the moon).
74.Mineral: a solid material of Earth´s crust with a definie composition.
75.Luster: the way light bounces off a mineral´s surface.
76.Streak: the color of the powder left when a mineral is rubbed against a hard,rough surface.
77.Hardness: how well a mineral resists scratching.
78.Cleavage: the tendency of a mineral to break along flat surfaces.
79. Ore: a mineral containing a useful substance.
80.Gem: a mineral valued for being rare and beautiful.
81.Nonrenewable resource: a resource that cannot be replaced within a short period of time or at all.
82.Rock: a naturally formed solid in the crust, made up of one or more minerals.
83.Igneous rock: a rock formed whn melted rock material cools and hardens.
84.Sedimentary rock: a rock made of bits of matter joined together.
85.Fossil: any remains or imprint of living things of the past.
86.Metamorphic rock: a rock formed under heat and pressure from another kind of rock.
87.Humus: decayed plant or animal material in soil.
88.Pollution: adding any harmfulsubstances to Earth´s land ,water,or air.
89.Rock cycle: rocks changing from one form into another form in a never-ending processes.
