| what does the electromagnetic spectrum consist of | a group of radiations that all travel at the speed of light |
| what is the order of radiations in the electromagnetic spectrum | radio
microwave
infrared
visible
ultraviolet
x rays
gamma rays |
| what is the relative frequency and wavelength of radio waves | 10^3m wavelength
10^4Hz frequency |
| what is the relative frequency and wavelength of micro waves | 10⁻²m wavelength
10⁸Hz frequency |
| what is the relative frequency and wavelength of infrared radiation | 10⁻⁵m wavelength
10¹²Hz frequency |
| what is the relative frequency and wavelength of visible light | 0.5x10⁻⁶m wavelength
10¹⁵Hz frequency |
| what is the relative frequency and wavelength of ultraviolet radiation | 10⁻⁸m wavelength
10¹⁶Hz frequency |
| what is the relative frequency and wavelength of x-rays | 10⁻¹⁰m wavelength
10¹⁸Hz frequency |
| what is the relative frequency and wavelength of gamma rays | 10⁻¹²m wavelength
10²⁰Hz frequency |
| can electromagnetic waves travel through a vacuum | yes |
| name sources, detectors, uses and dangers of radio waves | source: electronic circuits
detector: aerial
uses: communication, radio, TV
dangers: safe unless very concentrated |
| name sources, detectors uses and dangers of microwaves | source: electronic circuits
detector: aerial
uses: communications, satellites, heating water & food
dangers: burning if concentrated |
| name sources, detectors, uses and dangers of infrared radiation | infrared waves are emitted from hot or warm objects, they are heat waves
source: electronic devices, sun, warm objects
detector: electronic detector, heat sensitive papers, black bulb thermometer
uses: detector in security lighting, remote controls
danger: burning if concentrated |
| how does surface colour and texture affect infrared radiation emission and absorption | dark, matt surfaces are good absorbers and emitters of infrared radiation.
They are good at trapping heat energy.
light coloured, shiny surfaces are poor absorbers and emitters of infrared radiation (they are good reflectors).
They are not good at trapping heat energy, and rather keeping objects cooler. |
| name sources, detectors, uses and dangers of visible light | source: electronic devices
detector: eye, photographic film, electronic components
uses: seeing, photography, communication, laser surgery
dangers: burning , blindness if concentrated |
| name sources, detectors, uses and dangers of ultraviolet light | source: sun, gas discharge, lamps
detector: causes fluorescence in some objects, film
uses: sun tan lamps, making ions, making vitamin D, killing bacteria in water treatment plants
dangers: sun burn, skin cancer, retinal damage |
| name sources, detectors, uses and dangers of x rays | source: very fast electrons hitting a metal target
detector: photographic film
uses: imaging breaks/defects in bones, hidden devices
dangers: cell destruction, cell mutation, cancer |
| name sources, detectors, uses and dangers of gamma rays | source: radioactive nuclei decaying
detector: photographic film, gm tube
uses: medical tracers, killing cancerous cells, sterilisation of surgical equipment
dangers: cell destruction, cell mutation, cancer |
| what is the relationship between energy and frequency of waves | waves with higher frequency have greater energy than lower frequency waves |
