Electromagnetic radiation / electromagnetic wave
1. Its often abbreviated as emr / electro – magnetic – radiation,and one form of energy.
2. Example of EMR are,visible light¹,infrared radiation²,ultraviolet radiation³,radio waves⁴,x-rays,and gamma rays (all can travel at the speed of about 3.0 x 10⁸ ms ¯¹ ).
3. EMR has the component of electric and magnetic field which perpendicular to each other.
4. It exhibits wave-like behavior as travel through space.
5. Can travel through both,vacuum and medium of material.Most of the waves cannot travel through vacuum and need a medium for transmission.
6. Electromagnetic radiation carries energy and momentum that may be imparted to matter with which it interacts
1. Visible light is one of EMR,that visible to human eye.It has wavelength about 380 nm – 740 nm / 400-790 THz.( THz aka terahertz always refer to electromagnetic waves when they are propagating at frequency level).This is the range that human eye will respond.
Many of the species can see light out of visible spectrum,example,bee and birds and many other species can see the ultraviolet light,which help them to find a nectar in flower (Nectar is a sugar-rich liquid produced by plant ) .
Example of visible light, Lasers, sunlight, fire, LEDs, light bulbs
2. Infrared radiation also called heat radiation and has a wavelength longer than that of visible light.The image as what we see by using infrared radiation,figure 2 :
3. Ultraviolet light,is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm.It can be found in sunlight. Although ultraviolet radiation is invisible to the human eye, most people are aware of the effects of UV example, sunburn.
UV light is categorized as non ionizing radiation.Meaning, it does not carry enough energy per quantum ( the minimum amount of any physical entity ) to ionize atoms or molecules—that is, to completely remove an electron from an atom or molecule.
Sun as see by using UV light,
4. Radio waves has a wavelengths longer than infrared light.
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