Section 1 chapter 4

Electromagnetic Radiation (EMR) - a form of energy that travels in waves which includes radio waves, T.V. waves, microwaves, visible light, infrared light, ultraviolet radiation, x-rays, and gamma rays.All EMR (waves of energy) travels at 3.00 x 108m/sec in a vacuum (186,000 miles/sec).

Waves: (remember middle school science) Wavelength- lambda- crest to crest or trough to trough Frequency- measured in hertz (Hz)- cycles/second Amplitude- height of the wave from the middle or origin

Long wavelengths travel slower; short wavelengths travel fasterWavelength and frequency are inversely proportional

Speed of light=wavelength x frequency Problems: Determine the frequency of light if the wavelength is 4.257 x 10-7 m Determine the wavelength of the light if the frequency of the wave is 8.6 x 108Hz

White light- ROYGBIV- red has the lowest energy; longest wavelength; lowest frequency Violet has the highest energy; shortest wavelength; highest frequency Ground State- lowest energy state possible for an electron to occupy

Excited State- energy state that is achieved when an electron receives energy and moves to a higher energy level.

Flame Test- the color emitted by the element occurs when the electron falls to a lower stable energy level. the metal ion (cation) in a compound is the element producing the color. if more than one element is present, a dominant color may mask other colors. The color emitted by the element occurs when the electron falls to a lower energy level

Atomic Emission Spectrum- “fingerprint of the element” Each line of color produced corresponds to a certain frequency This frequency corresponds to the amount of energy given off (photon)

Atomic Emission Spectrum- “fingerprint of the element” Each line of color produced corresponds to a certain frequency This frequency corresponds to the amount of energy given off (photon)