| A | B |
|---|
| Charging by Contact | Also called charging by conduction involves the contact of a charged object to a neutral object.,  |
| Conductor | A substance through which electrons move freely, transmitting heat or electricity.,  |
| Electric Current | Electric current is the rate of charge flow past a given point in an electric circuit, measured in Coulombs/ second which is named Amperes.,  |
| Exothermic Reaction | A chemical reaction accompanied by the evolution of heat.,  |
| Gravity | The force that pulls objects towards earth,  |
| Infrared Rays | Electromagnet radiation having wavelength above microwave but below visible light,  |
| Layer | A thickness of some material laid on or spread over a surface,  |
| Metalloids | A nonmetal that in combination with a metal forms an alloy.,  |
| Opaque | Term used to describe a material that rejects or absorbs all light that strikes it.,  |
| Porosity | The ratio, expressed as a percentage, of the volume of the pores or interstices of a substance, as a rock or rock stratum, to the total volume of the mass.,  |
| Rolling Friction | Friction that occurs when an object rolls over a surface.,  |
| Static Electricity | The build up of electric charge on the surface of objects.,  |
| Transition Metal | An element in Group 3 through 12 of the periodic table.,  |
| Wedge | A simple machine consisting of a device that is thick at one end and tapers to a thin edge at the other,  |
