Given that our solar system is now about 4.6 billion years old, when will we need to start worrying about the sun running out of hydrogen for fusion?

The blank theory suggests that the sun, planets, and other celestial bodies of the solar system came from a cloud of dust and gas? a.) condensationb.) steady state c.) big bang d.) nebular

Compounds which are found naturally in the earth are called: a. ores b. composites c. rocks d.minerals

Name one type of data that h-r diagrams do not show.