earth rocks soil

            rock:a naturally formed solid in the crust, made up of one or more mineral.

                igneous rock:a rock formed when melted rock material cools and hardens.

                 sedimentary rock:a rock made of bits of matter joined together.

                           fossil:any remains or inprint of living things of the past.

      metamorphic rock:a rock formed under heat and pressure from another kind of rock.

                             humus:decayed plant or animal material in soil.

                   pollution:adding any harmful subtances to earth land, water, or air.

     rock cycle:rocks changing from one form into another in a never- ending series of processes.

                                               
                                           
                                                  
                                                
                                                         
                                                   
                                                   
                                                          

mineral of earth crust

               mineral:a solid material of earth crust with a definite composition.

                          luster:the way light bounces off a mineral surface.

      streak:the color of the powder left when a mineral is rubbed againt a hard, rough surface.

                            hardness:how well a mineral resists scratching.

                     cleavage:the tendency of a mineral to break along flat surface.

                                ore:a mineral containing a useful subtance.

                             gem:a mineral valued for being rare and beautiful.

nonrenewable resource:a resource that can not be replaced within a short period of time or at all

                                            
                                                               
                                                              
                                                       
                                                       
                                                            
                                                    
                                                           

earth changing crust

                    fault:a crack in the crust, whose sides show evidence of motion.

                             geologist:a scientist who studies earth.

                          magma:hot, molten rock deep below earth surface.

                                   lava:magma that reach earth surface.

                    weathering:the breaking down of rocks into smaller pieces.

                      erosion:the picking up and carrying away of pieces of rock.

                        deposition:the dropping off of bits of eroded rock.

   meteorite:a chunk of rock from space that strikes a surface(such as earth or the moon).
                                              
                                                                   
                                                                
                                                             
                                                                     
                                                             
                                                            
                                                        

earth and its neighbors

                   solar system:the sun and the objects that are traveling around it.

      planet:any of the eight large bodies that travel around the sun and shine by reflecting its light   

     gravity:a force of attraction,or pull between any objects and any other objects around it.

                  inertia:the tendency of a moving objects to keep moving in a straight line.

                                                  

                                                                                                             

lithosphere:the hard,outer layer of earth,about 100 kilometers thick.

crust:the rocky surface that makes up the top of lithosphere.

                         resource:any material that helps support life on earth

                                     hydrophere:earth water

                                                     
                                              

solid, liquid and gases

                    state of matter:any of the forms matter can exist in.

            melting point:the temperature at which a solid changes state into a gas.

            boiling point:the temperature at which a liquid chauges state into a gas

          freezing point:the temperature at which a liquid changes state into a solid.

                                                          
                                                           
                                                    
                                                

invisible light

electromagnetic:the productionn of magnetism by electricity and the prodution of electricity by magnets.                                   

electromagnetic spectrum:all the wavelenghts of visible and invisible light in order from short(gamma rays) to long (radio).

   laser:a device that produce a thin stream of light of just a few close wavelenghts.

                                            

colors of light

prism:a cutpiece of clear glass(or plastic)with two oppositesides in the shape of a triangle or other geometric shape.          

 

spectrum: a band of colors produced when light goes through a prism.

primary color:red,green,or blue; mixing these colors can produce all the colors of the spectrum.

primary pigment: magenta,cyan,yellow;material with any of these colors absorbs one primary color of light and reflects the other two.