Integrated Science

Boyce

Friday January 8, 20101. Objectives

a. Students will understand three physical characteristics (polarity, surface tension, and molecular bonding) of water in order to understand how they influence the movement of energy in the hydrosphere.

2. Homeworka. Moodle Pre-Assessment Testb. Moodle Lab Quizc. Lab #1 Completiond. Print out the pre-lab worksheet for Monday

3. In-Class Activitiesa. Post –Lab Discussionb. How many water droplets can a penny hold?

Polarity

• Polar– A polar molecule is one

that has opposite charges on opposite ends.

• Non-Polar– A non-polar molecule is

one that does not have ends that are oppositely charged

Bonding

• Cohesive Bonding– Occurs between molecules that

are the same. – In this case, the water molecules

sticking to each other.

• Adhesive Bonding– Occurs between molecules

that are different.– In this case, the bond

between the plant and the water droplets

Surface Tension• The cohesive bonding of water molecules

that results from the polarity of the water molecule.

• Water has high a surface tension. – This is demonstrated as a drop of water falls

from a spout.

– The drop clings to the tap, stretches, and finally lets go

– Check this out…

How did we do?Our learning goal was to understand…– Polarity– Bonding – Surface tension

The polarity of a water molecule leads to…

…cohesive bonding….

…which means that water molecules form a sticky surface...

…that will support things that should sink!