Across
- 1. Explosion throwing all the matter in the universe away from some central point.
- 4. Water is a?
- 7. Invisible matter.
- 9. Consists of everything observable.
- 10. The earth gets most of its energy from?
- 13. A positron was the first example of?
- 16. My professor calls himself?
- 17. If it is big and goes around a sun, it is a?
- 18. Is sometimes pictured as being like a solar system.
- 20. Has a positive charge.
Down
- 2. May have a hundred billion stars in it.
- 3. The change in frequency with relative velocity.
- 5. Which property of atoms is not periodic?
- 6. Solid object orbiting a sun.
- 8. About the mass of a neutron or proton.
- 10. Our sun is a?
- 11. Produces the correct conditions for a Big Bang.
- 12. The distance light travels in a year.
- 14. Has a negative charge.
- 15. They are held together by gluons.
- 19. If it goes around a planet it is a?