REVIEW 2

What is a galaxy?

• a star and it's surrounding planets
• billions of stars held together by gravity
• the big bang
• a cluster of nebulas

What type of electromagnetic radiation has the longest wavelength?

• gamma
• x-ray
• radio
• infrared

What type of electromagnetic radiation has the shortest wavelengths?

• microwaves
• visible light
• ultra violet
• x-rays

What type of EMR is heat?

• radio
• infrared
• visible
• ultra violet

What element made up about 75% of the early universe

• Hydrogen
• Helium
• Oxygen
• Carbon

What is the second most abundant element in the Universe?

• Hydrogen
• Helium
• Cargon
• Oxygen

Our universe is

• expanding, but the pace is slowing
• expanding, and the rate is increasing
• static and unchanging
• contracting

How old is our universe?

• 13.7 billion years old
• 4.6 billion years old
• 5,000 years old
• 13 years old

In the Big Bang our universe began it's

• explosion
• expansion

The Milky Way is what type of a galaxy?

• Spiral

• Spherical

• Elliptical

• Irregular