Universe Unit Test

Stars differ in all of the following ways except

• size
• temperature
• age
• composition

A main sequence star is powered by

• a.  nuclear fission reactions
• a.  the fusing of helium into the heavier elements
• a.  the fusing of hydrogen into helium
• a.  none of these

The coolest stars are __________; the hottest stars are __________.

• yellow; orange
• blue; orange
• yellow; yellow
• red; blue

Our star, the Sun, will likely end its life as a

• red giant
• black hole
• white dwarf
• supernova

A star forms from

• a nebula; gravity causes material to collapse until fusion begins
• particles or rock and metal that smash together to form a body that begins nuclear fusion
• a supernova explosion that releases material into space
• none of these

1.  Evidence for the Big Bang includes

• the background radiation in the universe
• blueshift indicating the universe is expanding
• ancient matter that appears to be star dust
• none of these

1.  Galaxies are

• made of billions to trillions of stars
• stationary in space
• elliptical, spiral or irregular
• none of these

The father away a galaxy

• the slower it is moving away
• the faster it is moving away
• the more stationary it appears
• none of these

By analyzing the spectrum of light from distant galaxies, astronomers learned that they

• are made of different materials
• are moving away from us
• are hotter the farther away they are
• are cooler the farther away they are

A star’s color is determined by the temperature at its core

• True
• False