Based on Hubble's observations, the universe is

• moving at the same speed
• going to explode
• moving apart
• not changing

What is an example of a wave with a long wavelength and low frequency?

• Gamma rays
• Infrared
• Radio
• Visible light

The frequency of infrared waves is..

• 10¹² Hz
• 10²⁰ Hz
• 10⁴ Hz
• 10¹⁵ Hz

What is the correct order of the visible light spectrum starting with the longer wavelength?

• Red, yellow, orange, blue, violet, indigo
• Violet, indigo, blue, green, yellow, orange, red
• Green, yellow, blue, indigo, red, orange
• Red, orange, yellow, green, blue, indigo, violet

What is an example of a wave with a short wavelength, high frequency, and high energy?

• Xray
• Microwave
• Visible light
• Infrared

An example of a wave with a short wavelength, high frequency, and high energy is a 

• X-ray
• Microwave
• Visible light wave
• Infrared wave

What gases are in the unknown mixture?

• Gas B & Gas D
• Gas C & Gas B
• Gas A & Gas D
• Gas D & Gas C

Frequency is..

• The distance of a wave from crest to crest.
• The shifting of waves away from Earth. 
• The amount of time it takes a wave to travel in one second.

If Sirius is 8.7 light years away from Earth, how long will the light to reach our eyes?

• 16 years
• 8.7 years
• 4.2 years
• 87 years

A light year is...

• The distance light travels in one year. 
• The speed of light.
• The revolution of the Earth around the Sun. 
• The amount of time it takes light to reach our eyes.