Across
- 4. (no space)have 2 valence electrons; become 2+ cations; slightly less reactive than alkali metals;
- 8. (no space)a table of the elements that displays their periodic properties in relationship with their atomic numbers
- 9. Came up with element symbols for the first 47 elements
- 12. (no space)the electrons in the outermost energy level of a neutral atom
- 15. The row on the periodic table
- 16. Used X-ray spectroscopy to determine the atomic number for each element
- 18. (no space)one or two valence electrons, easily making 1+ or 2+ cations; often found in alloys like sterling silver, steel;
- 20. have 4 or more valence electrons; on right of periodic table;
Down
- 1. (no space)elements in group 1; one valence electrons; very reactive and form 1+ cations; always found as compounds;
- 2. (no space)groups 13-16
- 3. group 17; 7 valence electrons so gain 1 to become 1- anions; highly reactive;
- 5. Made one of the first lists of 33 elements
- 6. almost 80% of elements; few valence electrons; left on periodic table
- 7. (no space)two valence electrons forming 2+ cations; first row is rare; second row is radioactive;
- 8. (no space)states that the properties of the elements vary in a periodic way with their atomic numbers
- 10. between metals and nonmetals; also called semiconductors;
- 11. First to organize elements in a table by increasing atomic mass
- 13. (no space)8 valence electrons except for helium; unreactive or inert;
- 14. Expanded on periodicity, group elements by atomic mass and developed the law of octaves
- 17. A set of elements in the same column
- 19. Said matter consisted of indivisible particles of elements