1. Atomic Structure 1) nucleus- the center of the atom and is made up off protons (+) and neutrons (0). 2) electron cloud- surrounds the nucleus and is made up of electrons (-) every atom has two main parts:

2. Electron Cloud the electron cloud is organized into energy levels 1 st energy level = 2 electrons 2 nd energy level = 8 electrons valence electrons – the electrons in the outermost energy level.

3. 0 available space for another electron electron cloud nucleus HYDROGEN atomic number – number of protons in the nucleus. balanced atom – equal number of protons and electrons; has no charge. 1 st energy level

4. 0 0 0 0 00 CARBON balanced atom 6 proton = 6 electrons 1 st energy level 2 nd energy level

5. LITHIUM 3 + FLUORINE 9 + balanced atom 3 proton = 3 electrons balanced atom 9 proton = 9 electrons

6. Meaning of Life balanced atoms = unhappy atoms stable atoms = happy atoms

7. Atoms become stable when they complete their outermost energy level. 2 ways to complete the outmost energy level: 1) find a home for their valence electrons 2) get electrons from other atoms. LITHIUM Li FLUORINE Fl

8. 1 Lithium & 1 Fluorine = Lithium fluoride FLi structure formula LiF

9. C H H H H Carbon & Hydrogen

10. 1 Carbon & 4 Hydrogen = Methane C H H H H CH 4 structure formula

11. Oxidation Numbers The oxidations number indicates if an atom is going to give up electrons or take in electrons in order to become stable. Positive oxidation numbers mean the atom is going to give up electrons. Negative oxidation numbers mean the atom is going to take in electrons

12. LITHIUM 3 + FLUORINE 9 + balanced but not stable Li +1 F -1 Stable and happy

13. C H H H H C -4 H +1 CH 4

14. ElementAtomic #Valance e - s Oxidation # N O K Al C Ne 7 8 19 13 6 10 5 6 1 3 4 8 -3 -2 +1 +3 +/-4 0

15. ion – an atom or group of atoms that has an electric charge. Li + O -2 Mg +2 F-F- polyatomic ions- a group of atoms that react as a single ion. NH 4 + ammonium NO 3 - nitrate SO 4 -2 sulfate PO 4 -3 phosphate

16. Polyatomic Ions AmmoniumNH 4 +1 AcetateC 2 H 3 O 2 -1 Hydrogen CarbonateHCO 3 -1 HydroxideOH -1 NitrateNO 3 -1 NitriteNO 2 -1 ChlorateClO 3 -1 CarbonateCO 3 -2 SulfateSO 4 -2 SulfiteSO 3 -2 PhosphatePO 4 -3

17. Chemical Formulas Chemical formulas have positive and negative ions when combined have their oxidation numbers equaling zero. Ca +2 O -2 + CaO calcium oxide Mg +2 + Cl -1 MgCl 2 magnesium chloride K+K+ + SO 4 -2 K 2 SO 4 potassium sulfate NH 4 + + S -2 (NH 4 ) 2 S ammonium sulfide Zn +2 + PO 4 -3 Zn 3 (PO 4 ) 2 zinc phosphate

18. Atoms become stable when they react with other atoms. When atoms react, they form a chemical bond. 3 Types of Chemical Bonds: 1) Ionic 2) Covalent 3) Metallic

19. Ionic bonds form as a result of the attraction between positive and negative ions. Na Cl + - NaCl sodium chloride table salt

20. Covalent bonds form when electrons are shared between atoms. O O + O O being happy some of the time is better than none of the time. O2O2

21. Metallic bonds form between positively charged metal ions and the free moving valence electrons. + + + + + + + + + + + + + + - - - - - - - - - - - - - - - - - - - - - - - - - - - - A “sea” of electrons moving around the positively charged metal ions