Polar Bears and Penguins

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.

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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