1. Unit 2 Chemical Bonding: Covalent 2.4 What are polar and nonpolar bonds? AIM: How do we determine if a bond is polar? DO NOW: A strontium atom differs from a strontium ion in that the atom has a greater 1. number of electrons 2. number of protons 3. atomic number 4. mass number Strotium atom:

2. TUG OF WAR DIRECTIONS: Look at the following combinations and predict which person would win the tug of war and by how much? FIRST PERSONSECOND PERSONWINNERBY HOW MUCH? Ms. Kasia Ms. AngelaMs. Michelle Mr. RosarioMr. Kaufman Mr. MolloyMr. Lissone Ms. Donna 10ft

3. IN CHEMISTRY WE CALL THE WINNERS ELECTRONEGATIVES

4. WHAT IS ELECTRONEGATIVITY? Tendency of an atom to attract electrons Higher electronegativity means you will attract electrons more EXAMPLE WINNERFLUORINE

5. READ THE PASSAGE Directions: Read the passage and complete the chart ELECTRONEGATIVITY DIFFERENCE DESCRIPTIONTYPE OF BOND FORMED ≥ 1.7 < 1.7 <0.4 0.4-1.7 Between 0.4 and 1.7 Atom with greater electonegativity gain the e - IONIC This will always be covalent COVALENT Atoms are shared equally NONPOLAR COVALENT Atoms are shared unequally POLAR COVALENT

6. NONPOLAR VS POLAR Directions: Read the passage and complete the chart TYPE OF BONDDESCRIPTION NONPOLAR BOND POLAR BOND A type of covalent bond in which both atoms attract the bonding electrons equally or nearly equally. Atoms attract the bonding Electrons unequally

7. LET’S TRY SOME Directions: Complete the following examples using notes COMPOUNDELECTRONEGATIVITIES OF EACH ELEMENTS MOST ELECTRONEGATIVE TYPE OF BOND FORMED H2OH2O HCl F2F2 CO 2 HH 2.1 OO 3.5 OXYGEN 3.5-2.1=1.4 1.4 is between (0.4-1.7) so it is polar covalent HH 2.1 Cl  3.2 CHLORINE 3.2-2.1=1.1 1.1 is between (0.4-1.7) so it is polar covalent FF 4.0 NEITHER 4.0-4.0=0 0 so it is Nonpolar covalent CC 2.6 OO 3.5 OXYGEN 3.5-2.6=0.9 0.9 is between (0.4-1.7) so it is polar covalent

8. NEXT STEPS Complete the Independent Practice If time permits, please complete FOOD FOR THOUGHT When you have completed the activity you may work on the following: 1.Your labs (I NEED ALL OF THEM) 2.REGENTSPREP.ORG