This week was packed with hands-on learning! We conducted labs all week in order to define matter, explore its properties, and investigate how it changes.
On Monday, we continued our look at whether air could be classified as matter. We began the class by placing Alka Seltzer tablets and water into a film canister. Then, quickly, but firmly, putting on the lid, flipping the canister over and watching the resulting science occur. With the expansion of gas created and nowhere to go, the gas caused the top of the canister to launch into the air, much to the delight and joy of the kids. Then, we added baking soda to vinegar and watched as it inflated a balloon on top of a graduated cylinder. The pictures below show the kids conducting their investigations.
On Tuesday, we watched a college professor use liquid nitrogen and 1500 ping pong balls to demonstrate that air takes up space. Much like our previous day's investigation, the video was pure science joy! Then, the students completed a CER in which they were asked to act as a lawyer to defend their client, Air, in its effort to prove that it is matter. The kids had to make a claim, air is matter. Then provide two pieces of evidence from our investigations to support their claim. Finally, they had to provide a reason to explain what their evidence meant and how it supported their claim.
For the remainder of the week we learned about and explored physical and chemical properties of matter. First, we discussed, in science, what a property is and how it is used. Then we compared and contrasted chemical and physical properties based on the information we had read.
In order to help make the concepts more concrete we did several labs about the physical properties of matter. On Wednesday we observed the physical properties of snack foods (pretzels, goldfish, teddy grahams, fruit snacks, twizzlers, mini Doritos). Students determined mass using scales, determined size using rulers, and used their senses to note shape, color, odor, texture, luster, and brittleness. Below are pictures from the activity.
Thursday, students looked at three more physical properties: conductivity, density, and viscosity. For conductivity, students used an open circuit and tried to close it using a variety of items. If the item was conductive, then the bulb would light. The kids loved lighting up the bulb. For viscosity and density, we first defined the terms. Then, students were given four liquids to observe and rank from most to least dense. To check their hypotheses, we created density columns which were so lovely and satisfying that, if you look at the pictures, you can see the students just staring in wonder.
Finally today, we switched gears from chemical and physical properties to chemical and physical changes. We reviewed definitions, examples, and determined how they varied from chemical and physical properties. To help make these concepts more concrete, the kid observed an elephant toothpaste demonstration, an egg in vinegar, and balloons in liquid nitrogen. Then, they participated in an investigation with milk and food coloring, Alka Seltzer and water, and instant snow.
All of the investigations we did in class can be done at home.
Egg and Vinegar: I love spreading the joy of science. :) If you have not done the lab, you need a container with a lid, vinegar (regular vinegar is fine) and one egg. Place the egg in the jar, fill with vinegar until the egg is covered, and close the jar using the lid. I would leave the egg in the jar for between 48 and 72 hours. When the egg comes out, you should be able to gently remove the shell by rubbing. The eggs will also bounce - be gentle. Be warned, they make a mess if they break.
Elephant Toothpaste: This works best with 20 vol (6%) hydrogen peroxide - this can be purchased online. However, it does work with regular 3% hydrogen peroxide but the reaction is slower. Here is a link to the lab. This one is messy but super fun.
Milk and Food Coloring: This investigation is fun to watch. Pour milk into a shallow container or bowl. It is more interesting if it is wider like a plate or pie pan. Place several different color drops of food coloring into the milk, leave some space between the drops. Next, dip the end of q-tip into liquid dish soap and quickly dip the q-tip into the center of the food coloring drop.