23 2.2.2 (i) electronegativity as the When is a molecule polar? Learners should: ability of an atom to attract the * Introduce the principle of electronegativity and how uneven bonded Students change the electronegativity of bonding electrons in a covalent electron pair sharing leads to bond polarity. atoms in a molecule to see how it affects bond; interpretation of Pauling polarity. See how the molecule behaves in * Use the online model to demonstrate how difference in electronegativity values an electric field. Change the bond angle to electronegativity influences the magnitude and direction of the dipole. 2.2.2 (j) explanation of: see how shape affects polarity. See how it Use this to explain Pauling electronegativity values, and introduce the works for real molecules in 3D. +/– notation. (i) a polar bond and permanent dipole within molecules * Ask learners to explain why HCl is a polar molecule. containing covalently-bonded Activity: * Review electronegativity; ask learners to identify most and least atoms with different electronegative elements in the periodic table. electronegativities * Explain how molecular / orientation of bonds and bond polarity (ii) a polar molecule and overall determine whether a molecule is polar overall (CO2 and H2O as dipole in terms of permanent examples). dipole(s) and molecular shape * Review understanding (also of shapes of molecules) using other examples. * Set related questions from textbook.
23 2.2.2 (i) electronegativity as the ability of an atom to attract the bonding electrons in a covalent bond; interpretation of Pauling electronegativity values 2.2.2 (j) explanation of: (i) a polar bond and permanent dipole within molecules containing covalently-bonded atoms with different electronegativities (ii) a polar molecule and overall dipole in terms of permanent dipole(s) and molecular shape When is a molecule polar? Students change the electronegativity of atoms in a molecule to see how it affects polarity. See how the molecule behaves in an electric field. Change the bond angle to see how shape affects polarity. See how it works for real molecules in 3D. Activity: Learners should: * Introduce the principle of electronegativity and how uneven bonded electron pair sharing leads to bond polarity. * Use the online model to demonstrate how difference in electronegativity influences the magnitude and direction of the dipole. Use this to explain Pauling electronegativity values, and introduce the +/– notation. * Ask learners to explain why HCl is a polar molecule. * Review electronegativity; ask learners to identify most and least electronegative elements in the periodic table. * Explain how molecular / orientation of bonds and bond polarity determine whether a molecule is polar overall (CO2 and H2O as examples). * Review understanding (also of shapes of molecules) using other examples. * Set related questions from textbook.
Chemistry%20A%20sample%20SoW%20using%20builder%20lessons%201-24.docx