Catalyst

• Fire write (3 minutes): Do you think the phrase “smelt-it-dealt-it” has a scientific basis? Why or why not? Remember that farts are made from methane, which is a gas.

III. Pressure vs. Altitude• Pressure decreases with altitude (as we go

higher up in the atmosphere)…why???– Gravity– Temperature decreases

IV. Pressure vs. Depth

• Pressure increases with depth (below the surface of the ocean)…why?– Weight of water

creates pressure

• Dolphin Kid, Son of Aquaman

The Sad Story of My First Love

Justify – TPS• Why did the people closer to the air freshener

canister smell it sooner then the people further away from it?

Lecture 6.3 – Diffusion

Learning Target• LT 6.2 – I can discuss how the diffusion of a

gas through a space is the result of the random motion of a gas molecule.

What is diffusion?

I. Diffusion• Diffusion is the movement of particles from

regions of higher density to regions of lower density.

• The random motion of gases explains the process of diffusion.

II. Random Motion1. Diffusion is not instant because of random

collisions of the gas with air molecules.– Example: Marshawn Lynch, “Beast Mode”

2. Gas molecules diffuse equally throughout a region of constant pressure.

You’ve Seen Diffusion Before!

Closing TimeClosing Time• Homework: HW6.1 due Friday, 1.24.2014• Remember this is for a grade!