Across
- 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
Down
- 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