Sept. 20 - Physical and Chemical Changes

Today we finished up the discussion of pure substances and mixtures.  Here are the fully completed notes:

• Pure Substances and Mixtures (solutions)

We talked about some ways to separate solutions and mechanical mixtures.  In "Life of Pi" a boy is stranded on a lifeboat, but he manages to get fresh water using solar stills.

The cone shaped thing near his boat is used to separate sea water into salt and fresh water.

Here's what it looks like closeup.  Sea water evaporates on the inside and fresh water is condensed onto the edges.

Here are some fun ways to separate a mechanical mixture of coins:

• Coin separators.
  https://www.youtube.com/watch?v=f0uDiue3R7w
  https://www.youtube.com/watch?v=vZaRgMOo-Ig

Next we moved on to Chapters 5.2 and 5.3

Physical and Chemical Properties

Learning Goals: Understand the difference between physical and chemical changes.

Success Criteria: You can describe some physical and chemical properties of some common substances.

We first completed some notes:

Handout: Physical and Chemical Property Notes

I then challenged you to describe some physical and chemical properties of milk.

Here's what some of you came up with:

Physical Properties:

• White and not transparent.
• Liquid at room temperature.
• Smells natural.
• Tastes bland.

Chemical Properties:

• Turns sour over time.
• Curdles with lemons.
• Can be made into yogurt or cheese.

Homework:

• Complete handout on pure substances and mixtures.
• Complete Density Lab if not done.
• Study for quiz by doing these questions from the textbook P. 198 #3-10, 12.

Have a good weekend and see you on Tuesday!