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Worksheet from side counter FIND YOUR NEW SEAT
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Pass back work Extra credit slips: pass out Presentation grades posted 3 rd period: finish presentations Tests will be graded by the end of Tuesday Go over Wednesday Work ethic
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Demo intro to reactions Elements vs. compounds Vocab cards Practice Kahoot check Valence electrons: revisit Objective: how do elements make up compounds?
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Volunteer to keep track of elements and compounds demonstrated in the demo
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Work on part 1 of your worksheet ElementCompound
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15 minutes to finish practice problems with your neighbor
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Go to kahoot.it on your iPad/laptop
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How do you find the number of valence electrons an element has by looking at the periodic table?
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How many valence electrons in Carbon?
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How many valence electrons in Nitrogen?
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How many valence electrons in Beryllium?
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How many valence electrons in Sodium?
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How many valence electrons in Argon?
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Back of worksheet Finish by Wednesday (more HW will be assigned Wed, collect on Th/F)
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½ sheet of paper for bellwork quiz Homework (compound vs. element) Write name and date 10/29/2014
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1. Is Xe an element, compound or diatomic element? 2. How many elements make up the compound Mg(SO 4 ) 2 ? 3. How many Sulfur atoms are there in the compound Mg(SO 4 ) 2 ?
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1. Is Xe an element, compound or diatomic element? 2. How many elements make up the compound Mg(SO 4 ) 2 ? 3. How many Sulfur atoms are there in the compound Mg(SO 4 ) 2 ? 4. How many Carbon atoms are there in the compound CH 3 COOCH 2 C 6 H 5 ?
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How do we go from elements on the periodic table to building compounds? We must first visit Lewis Dot Structures of single elements to determine how they will fit together.
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Look at the two pictures below. One is a Lewis Dot Structure of Sulfur and one is the Bohr model of Sulfur. How are they similar and how are they different?
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Each atom has 4 sides (top, bottom, left, right). Only 2 electrons can fit on each side. Place electrons 1 at a time clockwise or counterclockwise on each side before doubling up No more than 2 electrons can sit on one side of the atom Exceptions: Hydrogen and Helium only have 1 orbital These rules make it clear later on how atoms bond together
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Create Lewis Structures using beans With your partner: Create the Lewis structure for the elements on your note-taker using knowledge of valence electrons and the proper location of Lewis Dot electrons Once you have created it, draw it on your note- taker in the box indicated
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½ sheet of paper for bellwork quiz Write name and date 10-30-2014
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Draw the Lewis dot structure of Iodine (I) How many electrons does Iodine need to have a full outer shell? How many electrons does Hydrogen need to have a full outer shell?
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What are the rules for how do Lewis Dot Structures bond together to make compounds?
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IN COMPOUNDS ELECTRONS COME IN PAIRS! Only in rare circumstances do you see a lonely electron on an atom in a compound
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Electronegativity – the atoms desire for electrons or attraction to electrons Compare the following elements in terms of electronegativity: H vs. O C vs. O C vs. F B vs. F
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1. LEAST electronegative atoms usually go in the middle 2. More electronegative atoms like to have electron pairs un-bonded (floating around them 3. Hydrogen’s are always external (not central atoms) 4. Each atom must have a satisfied octet (8 valence electrons, 2 for hydrogen)
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Octet rule: atoms of main group elements tend to bond in such a way that each atom has 8 electrons in its valence shell. Bonds: each bond is a shared pair of electrons and each atom associated with that bond contains both electrons in its valence shell.
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1. Formal Charge = The charge on an atom based on its bonding configuration in a compound 2. Formal Charge = V – B 2 V = valence electrons of element in question B = bonded electrons of element in question Ex. C 2 H 2 Element: Carbon V = 4B = 8 = 4 2 FC = 4 – 4 = 0
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Goal: The structure of the compound must have the lowest possible formal charges on all atoms to be stable If formal charges are high, the compound likely does not exist in that form.
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Practice – with beans Create the following compounds with your beans and then draw them on your note-taker in the box provided H 2 OCO 2
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What would be a good definition for a bond after creating these structures? How many electrons would be required to make a double bond? A triple bond?
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Task: Step 1: add up all valence electrons for each atom in the compound Step 2: draw the Lewis Structure of the compound with electrons ONLY Step 3: draw the Lewis Structure of the compound by substituting bonds for electrons between atoms (2 electron = 1 bond, 4 electrons = 2 bonds, 6 electrons = 3 bonds)
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Task: Step 1: add up all valence electrons for each atom in the compound Step 2: draw the Lewis Structure of the compound with electrons ONLY Step 3: draw the Lewis Structure of the compound by substituting bonds for electrons between atoms (2 electron = 1 bond, 4 electrons = 2 bonds, 6 electrons = 3 bonds)
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Use the beans each time you create a compound If you need help with one, I cannot help you unless you have started with the beans so we can manipulate them
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Covalent bond: Shared pair of electrons Can be equal or unequal sharing polarity Ionic bond: Loss of gain of electrons in creating a bond Metal + non-metal (positive ion + negative ion)
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More Lewis Dot Structure Honors: formal charge with each atom in each compound!
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