Atomic Theroy

1. the system of electrons surrounding the nucleus of an atom.
6. the amount of matter stays the same, even when matter changes form
10. when two elements combine with each other to form more than one compound,
12. a given chemical compound always contains the same elements in the exact same proportions by mass.
14. negatively charged subatomic particle that can be either bound to an atom or free

2. An uncharged atomic particle that has a mass nearly equal to that of the proton and is present in all known atomic nuclei
3. A subatomic particle with a positive electric charge.
4. the total number of protons and neutrons in an atom
5. The smallest part of a substance that cannot be broken down chemically.
7. variation of an element that possesses the same atomic number but a different mass number
8. the weighted average mass of the atoms in a naturally occurring sample of the element
9. The total number of protons in the nucleus of an atom
11. A charged subatomic particle
13. a positively charged region at the center of the atom.