Atoms and Elements

2. Highly-reactive nonmetals in group 7A of the periodic table
5. A negatively charged particle
8. Atoms with the same number of protons but different numbers of neutrons
10. Found in lower left side and middle of periodic table; good conductors of heat and electricty
13. A charged particle
14. One- or two-letter abbreviation identifying unique atoms
18. Core of an atom
19. Element found in the d-block of periodic table; properties tend to be less predictable
21. Positively charged particle
23. Element found on the boundary between metals and nonmetals; exhibits properties of both
24. Negatively charged particle
26. Group of organic compounds with the same functional group
28. Dalton's thoughts that shape modern chemistry

1. Fairly reactive metals in group 2A of the periodic table
3. Element found in s- or p-blocks of periodic table; properties tend to be predictable
4. Z; number of proton's in an atom's nucleus
6. Found on upper right side of periodic table; poor conductors; gain electrons during chemical change
7. 6.02214 x 10e23
9. Average mass in amu of the atoms of a particular elements based on the relative abundance of the various isotopes
11. A; sum of protons and neutrons
12. Mass in grams of one morel of atoms of an element; numerically equivalent to the atomic mass in amu
15. Highly reactive metals in group 1A of the periodic table
16. 1/12 the mass of a carbon atom; approx. mass of proton or neutron
17. Neutral particles within the nucleus
20. Material with intermediate electrical conductivity that can be changed or controlled
22. Group 8A elements which are largely unreactive due to stable, filled p orbitals
25. A positively charged particle
27. Unit defined as the amount of material containing Avogadro's number of particles