Electromagnetic Waves

EM waves – waves that DO NOT need a medium to travel through, they can travel through a vacuum (empty space)

Examples of EM waves:• Radio waves – GPS, MRI, RADAR

• Microwaves – heating up food

• Infrared waves – heat lamps, warmth

• Light – what we can see

• Ultraviolet rays (UV) – causes cancer and vitamin D

• X-rays – too much exposure can cause cancer

• Gamma rays – radiation, hulk, nuclear weapons

EM WavesALL EM waves travel at the speed

of light (VERY FAST)At this speed, they can travel

around the would 8 times in one second

EM SpectrumEM Spectrum – range of EM waves

from low to high frequency

EM Spectrum

EM SpectrumLongest wavelength

Lowest frequency

Shortest wavelength

Highest frequency

EM Spectrum

Visible LightVisible Light – part of the EM

spectrum that humans can see

R O Y G B I V

Long wavelength

Low frequency

Low energy

COLD

Short wavelength

High frequency

High energy

HOT

R O Y G B I V The color you see is the wavelength that is

reflected while all other color wavelengths are absorbed

EX: If you see green, that means green is reflected and all other colors are absorbed – plants have chlorophyll

R O Y G B I VWhite is the reflection of all the

colors

Black is the absorption of all the colors

Questions1. Which EM wave has the longest wavelength?

Radio waves

Questions2. Which EM wave has the highest frequency?

Gamma waves

Questions3. What part of the EM spectrum can be seen by humans?

Visible Light

Questions4. Visible waves have a higher frequency than what other waves?

Radio, Microwave, Infrared waves

Questions5. What color of the visible light spectrum is considered to be the hottest with the highest energy and highest frequency?

Violet

Questions6. In a vacuum, all EM waves have the same?

A. WavelengthB. FrequencyC. Speed of lightD. Amplitude

Questions7. In the summer, people use sunscreen to prevent damage to the integumentary system. What type of rays do sunscreen help prevent from penetrating in and damaging your skin?

A. Gamma raysB. Ultraviolet raysC. Visible raysD. X-rays

Questions8. EM waves can transfer energy without a?

A. Electric currentB. MediumC. Magnetic fieldD. Source