2 Electromagnetic Radiation Electromagnetic radiation is energy that is transmitted from one place to another by light.Not all forms of electromagnetic radiation are visible.In fact, most electromagnetic radiation cannot be seen.X-rays, gamma rays, microwaves, radio waves, infrared, ultraviolet light, and visible light are some of the types of electromagnetic radiation.Electromagnetic radiation is known to travel in transverse waves.
3 Electromagnetic spectrum Lists all forms of electromagnetic radiation.The various types of radiation differ in wavelength and frequency
4 Wavelength and Frequency Wavelength is the distance between two consecutive waves.The symbol for wavelength is λ (Greek letter lambda)Wavelength is measured in meters.Frequency is the number of wave peaks that pass by a certain point in a given time period.The symbol for frequency is ν (Greek letter nu)Frequency is measured in Hertz (Hz) or the number of waves per second.
5 Practice ii iii Which wave has a greatest frequency? Which wave has a greatest wavelength?iii
6 Relationship between Wavelength and Frequency Wavelength and frequency have an inversely proportional relationship.As one increases the other decreases and vice versa.This relationship can be summarized by the following equation:c=λνC= the speed of light (roughly 3.0 x 108m/s)
7 Wavelength and Frequency Which type of electromagnetic radiation has the greatest wavelength?RadiowavesWhich types of electromagnetic radiation has the greatest frequency ?Gamma Rays
8 Visible Light Spectrum Which color light has the greatest wavelength?RedWhat type of light has the greatest frequency?VioletHow can you remember the colors in order from least frequency to greatest?ROYGBIV
9 Dual Nature of LightAll forms of electromagnetic radiation have wave-like properties.However, these types of light also behave like particles at times.For this reason we say that electromagnetic radiation has a dual wave-particle nature.
10 Light as a Particle? E photon=hν Picture each particle of light carrying a specific quantity of energy called a quanta.These particles of light are known as photons.Each color of light carries a different quanta of energy.The amount of energy of a photon is the frequency of the light times a constant h. (Planks constant) h=6.626 x 10-34J sE photon=hν
11 Practice Which color photon would have the greatest amount of energy? VioletWhich would have the least?Red