1. 3:00 2:59 2:58 2:57 2:56 2:55 2:54 2:53 2:52 2:51 2:50 2:49 2:48 2:47 2:46 2:45 2:44 2:43 2:42 2:41 2:40 2:39 2:38 2:37 2:36 2:35 2:34 2:33 2:32 2:31 2:30 2:29 2:28 2:27 2:26 2:25 2:24 2:23 2:22 2:21 2:20 2:19 2:18 2:17 2:16 2:15 2:14 2:13 2:12 2:11 2:10 2:09 2:08 2:07 2:06 2:05 2:04 2:03 2:02 2:01 2:00 1:59 1:58 1:57 1:56 1:55 1:54 1:53 1:52 1:51 1:50 1:49 1:48 1:47 1:46 1:45 1:44 1:43 1:42 1:41 1:40 1:39 1:38 1:37 1:36 1:35 1:34 1:33 1:32 1:31 1:30 1:29 1:28 1:27 1:26 1:25 1:24 1:23 1:22 1:21 1:20 1:19 1:18 1:17 1:16 1:15 1:14 1:13 1:12 1:11 1:10 1:09 1:08 1:07 1:06 1:05 1:04 1:03 1:02 1:01 1:00 0:59 0:58 0:57 0:56 0:55 0:54 0:53 0:52 0:51 0:50 0:49 0:48 0:47 0:46 0:45 0:44 0:43 0:42 0:41 0:40 0:39 0:38 0:37 0:36 0:35 0:34 0:33 0:32 0:31 0:30 0:29 0:28 0:27 0:26 0:25 0:24 0:23 0:22 0:21 0:20 0:19 0:18 0:17 0:16 0:15 0:14 0:13 0:12 0:11 0:10 0:09 0:08 0:07 0:06 0:05 0:04 0:03 0:02 0:01 0:00 Do Now Hw: Bond Type worksheet Draw electron dot diagrams for the following atoms: HydrogenOxygen

3. Imagine a tug of war between two hydrogen atoms to form a diatomic molecule of hydrogen (H 2 ) o How does the pull of one hydrogen atom on electrons compare to the pull of another hydrogen atom on electrons? o What would happen during a tug of war over valence electrons between two hydrogen atoms?

4. covalent bonding o Occurs when electrons are shared between atoms When it comes to covalent bonding, “sharing is pairing.” o Unpaired electrons pair in such a way that each atom completes its outer shell. Draw electron dot diagrams for each of the hydrogen atoms in the hydrogen molecule. o How many electrons does each hydrogen need to complete its outer shell? The hydrogens are bonded because they are holding on to the same electrons. WRITEDOWN

5. Covalent Practice – Water

6. It’s obvious that sodium and chlorine bond is ionic – because sodium is a very active metal – chlorine is a very active nonmetal It is obvious that diatomic molecules such as H 2 contain covalent bonds – two identical atoms have the same pull on electrons But what type of bond is found between hydrogen and oxygen in water? o Oxygen is a nonmetal. o Hydrogen, being at the top of the family, is a metalloid. o They are not as different as sodium and chlorine, nor are they as similar as two hydrogens. Some measure is needed to show how different atoms’ pulls on electrons are. It is electronegativity.

7. The most metallic element is... o Its electronegativity is... The most nonmetallic element is... o Its electronegativity is... The electronegativity difference is... T HIS IS THE LARGEST ELECTRONEGATIVITY DIFFERENCE POSSIBLE. francium. 0.7, the lowest. flourine. 4.0, the highest. 3.3

8. The largest electronegativity difference possible is that between francium and fluorine. It is 3.3 o This represents the greatest ionic character. The smallest electronegativity possible is that found within diatomic molecules or between other very similar atoms. It is 0 o This represents the least ionic character. The midpoint is about … o This represents 50 percent ionic character. o It is the dividing line between ionic and covalent. o An electronegativity difference of 1.7 or more represents an ionic bond. Less than 1.7 is covalent. 1.7 WRITEDOWN

9. Fill in the table below to determine the bond type in water: The electronegativity difference is less than 1.7 The bonds between hydrogen and oxygen are covalent. ElementElectronegativity Oxygen Hydrogen Electronegativity Difference

10. Not all covalent bonds are created equal. o In the bond between chlorine atoms in a chlorine molecule (Cl 2 ), the electronegativity difference is 0.0, and the atoms share equally. o In a hydrogen chloride (HCl) molecule, the electronegativity difference is not 0.0, and the atoms don’t share equally. Fill in the table below: The bond is covalent, but the atoms don’t share equally. Chlorine is more electronegative. It has a stronger pull on electrons. o The shared electrons will be displaced closer to the chlorine. o This will make the charge on the chlorine side of the bond slightly negative, and on the hydrogen side of the bond slightly positive. ElementElectronegativity Chlorine Hydrogen Electronegativity Difference

11. In hydrogen chloride the hydrogen side of the bond is slightly positive, and the chloride side of the bond is slightly negative. The earth has opposite ends just like the hydrogen chloride molecule. The opposite ends of the earth are called... The adjective used to describe the bears living at the poles is... Bonds with oppositely charged ends are called polar bonds.NS poles. polar. WRITEDOWN WRITEDOWN

12. Three types of chemical bonds: o ionic, o polar covalent, and o nonpolar covalent Bond type is determined by electronegativity difference. 0.00.41.7 CovalentIonic NonpolarPolar WRITEDOWN

13. Regents Questions