Periodic Table

2. element with properties of both metals and nometals
8. the amount of energy needed to remove an electron from an atom in the gas phase
10. an atom that does not have a neutral charge; it is either positive or negative
13. measure of an atom's tendency to attract shared electrons when chemically bonding
14. elements in the second leftmost column; 2 valence electrons
15. 18th column of elements on the periodic table; stable and nonreactive
18. elements lacking in metallic characteristics like conductivity, malleability, and luster
19. created by Mendeleev; when elements are ordered by atomic number, their characteristics show a repeating pattern

1. "d" block on the periodic table or groups 3 through 12
3. the distance from the center of the nucleus and the outside electron shell; the size of an atom
4. Russian chemist who created one of the first Periodic tables
5. elements in the "s" and "p" blocks on the periodic; represent the predictable trends on the periodic table
6. horizontal rows of elements; denote how many electron shells those elements have
7. elements that lose valence electrons to form cations; usually high in malleability, conductivity, and luster
9. positively charged ion that has more protons than electrons
11. negatively charged ion that has more electrons than protons
12. 17th column on the periodic table; they have 7 valence electrons and are the most reactive elements
16. vertical columns in the periodic table; each one has the same amount of valence electrons
17. reactive elements in the leftmost column of the periodic table