em spectrum (book)

qtr 1, periodicals

em spectrum

continuous range of electromagnetic waves, in order of frequency/wavelength

radio waves

longest of all electromagnetic waves

radar

acryonym for radio detection & ranging

gps

radio waves — global positioning system

rfid

radio waves — radio frequency indentification

mri

radio waves — magnetic resonance imaging

heinrich hertz

discovered radio waves in 1887

sun and jupiter

radio waves — extraterrestrial source of radio waves

james clerk maxwell

discovered microwaves in 1864

microwaves

2nd longest em wave, mainly used for communication

microwave doppler radars

microwaves — used in weather forecasting

microwave tomography

microwaves — imaging technology used to assess/monitor progress of treatment of breast cancer

microwaves / infrared

em waves in remotes

infrared

em wave that has lower frequency than the red parts of visible light, can be felt as heat

below red

meaning of infrared

william herschel

british astronomer who discovered infrared waves in 1800

heat lamps

infrared — used by physiotherapists, emits infrared radiation to heal sports injuries

visible light

em wave only seen by the naked eye

isaac newton

discovered the range of wavelength of visible light

roygbiv

visible light — red, orange, yellow, green, blue, indigo, violet

photosynthesis

visible light — how visible light is used by plants

ultraviolet radiation / uv rays

em wave after visible light

johann wilhelm ritter

german physicist that discovered uv rays

uvc

uv ray — mostly absorbed by the atmosphere, does not reach earth’s surface

uvb

uv ray — mostly filtered by the ozone in the atmosphere, affects the topmost layer/epidermis of the skin

uva

uv ray — 95% of the solar uv that reaches earth, penetrates the dermis of the skin more deeply

sun

uv ray — major source of uv rays

blacklight

another name for uv lights

vitamin d

uv ray — production of this vitamin in the body is stimulated by uv rays

x-ray

em wave that is the 2nd most ionizing, produced by the sun & other stars

roentgen ray

another name for x-rays

wilhelm conrad roentgen

german physicist who discovered x-rays

soft or hard

2 classifications of x-rays

soft x-rays

x-ray — lower energy, can penetrate soft substances like flesh & bones

hard x-rays

x-ray — higher energy, more penetrating, mainly industrial applications

gamma rays

most ionizing em wave, given off by radioactive elements

astronomicals objects

gamma rays — sources of gamma rays, such as sun, interstellar clouds, remnants of supernovae

paul villard

french chemist & physicist that discovered gamma rays in 1900

food radiation

gamma rays — kills bacteria/insects/parasite that can cause foodborne disease

radiotherapy

gamma rays — process that destroys cancer cells