ROYGBIV FORMAT NUMBER LINE FORMAT

June 5 / 5 Act F 96 The Electromagnetic Spectrum LEARNING TARGET: I can identify and describe the parts of the electromagnetic spectrum CH Q What are the characteristics of electromagnetic waves? VOCAB: Electromagnetic spectrum infrared Electromagnetic wave ultraviolet

Electromagnetic Spectrum (EM Spectrum) VOCAB: Electromagnetic Spectrum (EM Spectrum) electromagnetic wave infrared ultraviolet continuous range of wave energy from very long radio waves to very short gamma rays transmits energy across distance using electric and magnetic fields "below red" – long low energy waves associated with heat (but does NOT require a medium) "above violet" – short high energy waves associated with skin cancer and cataracts

PROCEDURE AND DATA MATERIALS: PROCEDURE: Read on pg. F 37-41 DATA: WS 96.1 The Electromagnetic Spectrum WS 96.2 Drawing the E-M Spectrum

for FRONT of WS 96.2 copy below R O Y G B V Tour of EM video – 5 mins

amount reaching Earth surface BACK of WS 96.2 copy below type of wave transverse - Electromagnetic Wave (SPECTRUM) amount of heat more than VL red red greatest heat of VL action of wave can be absorbed, reflected or transmitted amount of energy least greatest radar heat food cell phones heat up objects remote controls human vision sterilize objects treat cancer uses radio / TV view body skin cancer cataracts danger genetic mutations amount reaching Earth surface most UV absorbed by atmosphere (all xray and gamma) greatest amount produced by the Sun see next slide

all have wavelength, peak/crest, trough, and amplitude up to 1000s 103 10-2 10-5 10-7 10-8 10-10 10-12 all have wavelength, peak/crest, trough, and amplitude parts of wave

POST DISCUSSION What would the result of the experiment have been if Herschel had not used a control? no discovery of invisible infrared energy. And Ritter would not have built on that and discovered ultraviolet energy) Herschel video – 3 mins Ritter video – 1 min

Venn Diagram comparing Infrared and Ultraviolet Lower frequency Longer wavelength Less energy Not Visible Stimulates molecules in skin to produce heat Generally not damaging to skin & eyes Uses – remote controls, night vision, glasses Higher frequency Shorter wavelength More Energy Visible to the eye Does Not heat up skin Damages skin & eyes Uses – telescopes, sanitizing medical equipment Electromagnetic energy Lots given off by the sun Reflect, Refract & Absorb E-M Wave Comparison

- Discuss and answer Q 1&2 on pg. F 41 ANALYSIS - Discuss and answer Q 1&2 on pg. F 41 ANS CH Q What are the characteristics of electromagnetic waves? A: they have a very wide range of wavelength (energy) - only a very small part can be seen by humans – all can be transmitted, absorbed or reflected by a medium, but do NOT need a medium HOMEWORK None