Across
- 4. a version of an element
- 5. is a isotope of hydrogen tieh 2 neutrons and one proton
- 8. it has 1 proton and 1 neutron, is another isotope of hydrogen
- 9. a big star that is the center of our galaxy
Down
- 1. an isotope of hydrogen with only one proton
- 2. any basic substance that is used in or produced by a reaction involving changes to atoms or molecules
- 3. it is the smallest part of matter
- 6. also called chemical change or chemical phenomenon
- 7. is an element that is used to inflate ballons that can go away