| A | B |
|---|
| Radiation | The transfer of energy by electromagnetic waves |
| Electromagnetic Spectrum | Electromagnetic waves are classified according to this |
| Photons | Tiny bundles of radiation that have no mass |
| Radio Waves | The kind of electromagnetic radiation with very long wavelength and very low frequency |
| Modulation | The process of varying radio waves |
| Microwaves | The radio waves with the highest frequency and energy |
| Infrared Radiation | Has a wavelength slightly longer than visible light |
| Visible Radiation | The only part of the electromagnetic spectrum you can see |
| Ultraviolet Radiation | Has a higher frequency than visible light, and as a result its photons are more energetic and have greater penetrating power |
| X-ray | Has a shorter wavelength and higher frequency than ultraviolet radiation |
| Gamma Rays | Has the highest frequency of all the electromagnetic waves |
| Opaque Materials | Absorb or reflect all light and you cannot see objects through them |
| Transparent Materials | Allow light to pass through and you can clearly see objects through them |
| Translucent Materials | Allow light to pass through but you cannot clearly see objects through them |
| Incandescent Light | Produced by heat |
| Fluorescent Light | Produces light without excessive loss of energy due to heat |
| Reflection | Occurs when a wave strikes an object and bounces off |
| Refraction | The bending of waves caused by a change in their speed |
| Diffraction | The bending of waves around their barrier |
| Diffraction Grating | A piece of glass or plastic made up of many parelell slits |
