Thursday, August 26, 2010

Solutions Suspensions and Colloids

Today we started class identifying physical and chemical properties and changes. We watched a BrainPOP on physical and chemical changes and took the quiz. The amount of perfect scores was astounding.

For notes we covered solution, suspensions, and colloids. Solutions are homogeneous well mixed mixtures where a solute is spread out in a solvent. Suspensions are heterogeneous and will separate and settle over time because the larger particles are affected by gravity or perhaps the mixed substances have different densities. Colloids are weird because they should be suspensions, but the particles are so tiny that they constantly bump into each other and stay suspended.

We also looked at this solubility graph and answered a variety of questions. There are many ways to word questions based on this graph and students did well answering them.

We finished class by making observations of marshmallows. Students used their senses to make qualitative measurements and used rulers, balances, and calculators to make some quantitative measurements. The activity ends with microwaving a marshmallow - which is fun to watch. Fourth saw the magic today and third will see it tomorrow.

Tonight's homework will be boxes E and H on the green sheet

Are you smart enough chemistry-wise to understand this joke?

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