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Jump Jump PowerPoint Presentation

Jump Jump

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Jump Jump

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  1. Criss-cross notes Jump Jump

  2. Criss-Cross Method Criss-cross is a _________ to help you find chemical __________ when you _________ atoms. shortcut formulas combine **Formulas contain both the ________ in a compound and the _______ of that element. elements amount

  3. How Many? 1 sodium NaCl = 1 chlorine 1 magnesium MgCl2 = 2 chlorines This number is called a ________ subscript It tells you the _______ of the atom ________ in front of it! amount directly

  4. To get started… First – you need to determine the _________ number for each atom. oxidation You can find them in the ______- ______ corner on the Periodic Table. upper right

  5. Cl Oxidation Oxidation numbers are the _____ that will form when atoms _________ their _________ shells. ions complete valence Oxidation number Cl-1

  6. More than one? Many atoms have more than one oxidation state! We will use the ______ one listed! first (This is the one most _________ formed in nature!) commonly

  7. Criss-Cross will make you... Find the correct formula for a compound!! • Use the oxidation #’s • Put the _______ one first positive H+1 + O-2  H2O

  8. What just happened? By switching the numbers, the _________ number of one atom becomes the _________ for the other! oxidation subscript This also makes sure that we end up with a _______ compound – all the ________ of the ions add up to ______. neutral charges zero

  9. Stuff to remember… ‘Ones’ are ________. (Think Math!) invisible If both of your ions have the _____ oxidation number -- ______ to the ______ common number! same reduce lowest It will make more sense after examples…

  10. Criss-Cross practice +2 -1  CaBr2 Ca + Br +2 -1 Mg+ Cl  MgCl2 +2 -2 Sr2O2  SrO Sr + O

  11. What's my name? Don’t forget the rules for naming: 1. ______ always goes first! Metal 2. ________ goes second – and ends in _____! Nonmetal “-ide” Have fun!!!