1. Isotope Same element with a different mass

2. Ion Atoms or molecules with an electrical charge

3. Cations Positively charged atoms/molecules

4. Anions Negatively charged atoms/molecules

5. amu Atomic mass unit

6. Atomic number Number of protons

7. Mass number Protons + neutrons (amu unit)

8. Nuclide The nucleus of an atom

9. Alpha particles Helium nuclei Mass of 4 amu Charge of +2

10. Ionic compounds (cpds) Metals attached to nonmetals Known as formula units NOT TRUE MOLECULES

11. Molecular Cpds (or Covalent) Nonmetals attached to other nonmetals TRUE MOLECULES

12. Diatomic elements The 7 diatomic elements are also true molecules.

13. Periodic table The rows are called periods The columns are called families or groups

14. Metals Conduct electricity and heat Malleable Ductile Very reactive and unstable Silver/grey solids (Exceptions Au/Cu)

15. Nonmetals Insulators (don’t conduct heat or electricity) Brittle solids Some gases Not very malleable or ductile

16. Metalloids Found along the staircase Don’t fit neatly into the metal or nonmetal category. Contain some characteristics of each group.

17. True metals Alkali family (First column) Alkaline Earth family (Second column)

18. Nonmetals Noble gases (He family) Halogens (F family) Chalcogens (O family)

19. Transitional metals Most create very colorful cpds All are silver or grey solids except Hg (silver liquid), gold (yellow solid) and copper (brown solid). These have all of the characteristics of true metals but to a lesser degree.