Across
- 2. One of a class of elements having properties intermediate to metals and nonmetals
- 3. The number of protons in the nucleus of an atom of an element
- 5. A positively charged subatomic particle found in the nucleus of an atom
- 7. An arrangement of elements into rows and columns according to similarities n their properties
- 11. A subatomic particle with no charge and a mass of 1 amu
- 13. Any member of a group of gaseous elements in Group 0 of the periodic table
- 14. A unit of mass equal to one-twelfth the mass of a carbon-12 atom
Down
- 1. First theory to relate chemical changes to events at the atomic level
- 4. The total number of protons and neutrons in the nucleus of an atom
- 5. Elements arranged in order of increasing atomic number in a periodic repetition of their physical and chemical properties
- 6. Any member of the nonmetallic elements in Group 7A of the periodic table
- 8. Atoms of the same element that have the same atomic number but different atomic masses due to different number of neutrons
- 9. Stream of electrons produced at the negative electrode of a tube containing gas at low pressure
- 10. A negatively charged subatomic particle
- 12. The dense central portion of an atom, composed of protons and neutrons