Polar Bears and PenguinsMaking Sense page 135Unit 2
Investigation IVThe ability of an atom to attract electrons shared
between two atoms is called electronegativity.
High electronegative atoms (polar bears) gain a - (partial
negative)
Low electronegative atoms (penguins) gain a + (partial
positive)Making Sense -133
2Water Molecule:Oxygen attracts the shared electrons towards
itself so it is partial negative. Hydrogen is less electronegative
so the shared electrons are pulled away. It becomes partially
positive. Unit 2 Investigation IV
Direction of pull There is a crossed arrow to show the direction
of the dipole in HCl. The crossed end of the arrow indicates the
positive (+) end of the polar bond and the arrow points in the
direction of the negative (-) end.
4
Nonpolar molecules They have symmetrical shapes like linear and
tetrahedral and identical surrounding atoms. (Bonded electrons are
being pulled but they are canceled out.
5Unit 2 Investigation IV
Polar moleculesIt is not symmetrical. There are different
shapes.6
