Atomic Theory Crossword

2. total number of protons and neutrons that make up the nucleus of an isotope
4. the smallest particle of an element that retains the chemical properties of that element
6. a general term for a specific isotope of an element
9. atoms of the same element that have different masses
10. 1/12 the mass of a carbon-12 atom
13. if two or more different compounds are composed of the same two elements then the ratio of the masses is always of small whole numbers
14. forces between protons and neutrons that hold the nuclear particles together
15. concluded that all cathode rays are composed of negatively charged particles known as electrons

1. chemical compounds contain the same elements is exactly the same proportions by mass regardless of the size of the sample
3. matter is neither created nor destroyed during chemical and physical reactions
5. the number of protons of each atom of that element
7. weighted average of the atomic masses of the neutrally occurring isotopes of an element
8. Proposed an explanation for the law of conservation of mass
11. not the animal, the amount of a substance that contains as many particles as there are atoms in exactly 12g of Carbon-12
12. concluded that there is a dense positively charged bundle of matter in the center of the atom called the nucleus