If you can't explain it simply, you don't understand it well enough. ~Albert Einstein

Sunday, August 25, 2013

Week 4: Describing Matter - Pure Substances and Mixtures

Last week we talked about the properties and changes of matter.  Then we took our learning and applied it to an experiment: Banana and the Yeast Lab. We created a controlled experiment where compared the decomposition rates (dependent variable) between bananas. To see if yeast (independent variable) influences the decomposition of the banana we had to cover at least one banana sample with the substance and leave the other banana alone. To make our observations and avoid a lot of mess, we enclosed the banana samples in Ziploc bags. I am working on a video of this lab so stay tuned...

This week, we will continue making observations on what we observe happening to our banana samples.  Our focus this week is to identify any changes over the next few days and draw conclusions based on those observations. 

While we are experimenting, we will also begin learning about pure substances and mixtures. It's vital to tie everything we have been learning into our overarching Essential Question (You know the slide that I show you almost every day?). Instead of writing out a long-winded explanation I think a nice visual (or two) may be in order! 

But first let's take a quick commercial break and watch this video.

Not bad, right? Okay so matter can be broken down into two categories: Pure Substance or Mixture. So here is the work we've been doing this week on this topic:


How do you decide if something is a pure substance or mixture? Let's look at this in more detail.

Pure substances are substances that cannot be broken down any further because they are already in their simplest form. Examples of pure substances are elements and compounds. Mixtures, on the other hand, are physically-combined substances.  Mixtures can either be homogeneous (uniform throughout or can't see every substance that is in the mix) or heterogeneous (not uniformed throughout and you can pretty much see everything in its composition). Another name for a homogeneous mixture is a solution



Have you heard that there is some real science behind macaroni salad?





...and even more!



Whoa! Did someone just say there's a test next week?

Okay folks, here are some links to a few review activities I found online:
The Study of Change
Classification of Matter