2Electromagnetic 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.
3Electromagnetic spectrum Lists all forms of electromagnetic radiation.The various types of radiation differ in wavelength and frequency
4Wavelength 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.
5Practice ii iii Which wave has a greatest frequency? Which wave has a greatest wavelength?iii
6Relationship 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)
7Wavelength and Frequency Which type of electromagnetic radiation has the greatest wavelength?RadiowavesWhich types of electromagnetic radiation has the greatest frequency ?Gamma Rays
8Visible 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
9Dual 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.
10Light 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
11Practice Which color photon would have the greatest amount of energy? VioletWhich would have the least?Red