Big History Crossword Puzzle

1. / group of stars formed what?
5. / This was a relatively cool and uniform place before stars.
6. / Some energy is converted when you add energy to a pot of water or a group of atoms.
8. / They will simply burn out if there isn't enough fuel.
9. / they formed out of galaxies.
10. / What will only very large stars end up froming?
12. / they formed out of a galaxy cluster.
13. / A star will eventually consume all of these substances to power its nuclear fusion.
15. / These events are the Earth's way of maintaining equilibrium during periods of change.
16. / The process by which the planet's chemical composition is determined.
18. / They are created from the atom clouds that are left over.

2. / It is the death and massive explosion of a star.
3. / This condition may result in a continuation of life on Earth.
4. / They produce enough helium to begin burning helium when the hydrogen fuel runs out.
7. / They could be big and composed of gases or smaller and composed of rocks like our Earth.
9. / created gas clouds by bringing together individual hydrogen and helium atoms.
11. / They begin to light up all over the universe.
13. / It is a energy.
14. / Formed by the dramatic explosions of dying stars.
17. / It takes a lot of heat to fuse them together.