May 20th

Did You Know…? The Incas based their measurement of time on how long it took to boil a potato.

Good afternoon,

After completing our Math test today, we continued to explore chemistry. We have been talking about mixtures, but so far we have only worked with physical changes. We know this because we have not chemically changed any of our materials. This is why we were able to use our separating techniques to separate our mixtures back into their original parts. Another example of a physical change is water. Water can exist in three different forms: ice, liquid water, and water vapour. These correspond with the three states of matter: solid, liquid, and gas. Even if solid water (ice) melts into a liquid (liquid water), it is still just water. We have not chemically changed anything about it. That doesn’t mean that water isn’t unique. In fact, water is very unique! Today we explored one of the aspects of water that makes it so unique… it’s surface tension. The particles in water are more strongly attracted to one another than many other liquids, or has strong cohesion. This means that the particles actually pull themselves closely together if possible. One way that we demonstrated this was with wax paper. The students put vegetable oil onto the paper first and noticed that it simply spread out across the paper. The particles in vegetable have weak cohesion. However, when we added water onto our wax paper, we saw that it stayed together in drops and bubbles. The water pulled itself together as much as possible. This is a great way to see the strong cohesion of water particles. In fact, the particles of water have such strong cohesion, that they actually create what we call a “skin” across the surface of water. This thin barrier is actually much tougher to break through than you would think. We added some pennies to a very full glass of water. The water was able to reach the top and continue above the rim of the glass, without spilling. It formed a bubble of water above the rim. Again, the strong cohesion causes the particles to pull as closely together as they can, creating a “skin” or having a high surface tension. Tomorrow we will see how to break this surface tension!

In Computers today we completed the activities below. The first is a chemistry activity that introduced students to some of the concepts that we will discuss tomorrow and Friday on chemical changes. The second and third links were for FNMI Week. They enabled students to design their own wampum belts or their own glass beadwork design. We had a lot of fun. If you want to learn more about these two First Nations’ arts, click on the links to see some history and examples.

Kitchen Chemistry – http://pbskids.org/zoom/games/kitchenchemistry/virtual-start.html

Virtual Wampum Belt – http://www.nativetech.org/beadwork/wampumgraph/index.html

Interactive Beadwork Designer – http://www.nativetech.org/beadwork/beadgraph/index.html

We also listened to two FNMI stories today. The first was called, “The Big Rock Story,” which you can listen to at home by following the link below:

The second was “A Promise is a Promise” by Robert Munsch. This is a modern retelling of traditional legend and folklore, and it is very different from most of Robert Munsch’s other stories. It is based on a creature that parents would warn their children about so they wouldn’t go on the sea ice. This story is told in the Northwest Territories to keep Inuit children safe. If you want to listen to this one again at home (or another Robert Munsch story) you can visit his website: http://robertmunsch.com/book/a-promise-is-a-promise-2.

Agenda:

Read 20 minutes

Math: