Intermolecular Forces and
Phase Change
by Kim Law and Alex
Shames!
(and Mr. Bennett)
How do geckos stick to things? Which
intermolecular force is this?
http://www.youtube.com/watch?v=H
Tbrsx1zARs (Start at 0:40) Gecko
feet have a large surface area
because of all the hairs. Which IMF
increases with surface area?
Scientists made a substance to mimic
the properties of the gecko’s foot. What
kind of properties should their material
have?
Which structure matches which
liquid?
Oil
Honey
Hint: Think about
each liquid’s
consistency. Is it
slow moving or fast
moving?
Viscosity
Resistance to deformation
Commonly thought of as thickness of liquids
More IMF = more viscous (think honey vs.
water)
Why does sweating cool us off?
This marathon runner is
ridiculously photogenic-probably because he’s
staying nice and cool thanks
to sweating. Why is that?
How come this salad dressing
separated?
The olive oil and vinegar
clearly don’t mix. Why can’t
they just get along?
Here’s the structure of olive oil
Here’s the structure of vinegar
Why does ice cream melt on a hot
summer day?
M&M’s don’t melt on a hot
summer day don’t melt.
What does this mean
about the intermolecular
forces in each material?
How does this spider walk on water?
Would the spider be able to
do this on oil? Why or why
not? Here’s he structure of
oil again as a reminder.
Surface Tension
Resistance to external force.
Stronger IMF = greater surface
tension
http://ga.water.usgs.gov/edu/gra
phics/surfacetension-diagram.gif
The End
Now be ready for a pop quiz!
Shout out to Katie Shi