Apologia Physical Science Lab – Module 2

Welcome back!

This session we are studying air.

Experiment 2.1 Evaporation and Temperature

This experiment represents our body temperature when we sweat.

Calling for a bulb thermometer….this is the best we could find.

While waiting for the water in the glass to reach room temperature, place the thermometer on the plastic and take a reading. After about 15 minutes, soak the two cotton balls in the water. Remove the cotton balls, squeezing out the excess water and place them around the bulb of the thermometer. Wait a few minutes and read the temperature. Compare to the previous temperature.

The thermometer in the plastic read the temperature of the room. When placing the cotton balls on the thermometer it still read room temperature (because the water was at room temperature) – but – ended up dropping a little because the water was evaporating and cooling the cotton balls. Kind of like how sweating cools our bodies.

Experiment 2.2: Oxygen and Fire

Fire needs oxygen to burn. What happens when there is MORE oxygen than usual?

After putting on some safety goggles, fill a 2 liter bottle with hydrogen peroxide and add a teaspoon of yeast. Moving quickly, cover the opening of the bottle with a balloon. Get a good seal and gently shake the bottle. Once the balloon inflates with the trapped gas, gently remove it holding the neck of the balloon.

Everyone knows what happens when you deprived a lit candle of oxygen…..

With the candle lit, and glass jar in place, tilt the jar so the opening of the balloon fits under it and SLOWLY let the oxygen out of the balloon.

Well, I wasn’t fast enough with the camera…but, what you would have seen with your own eyes was a big, bright flame coming from the candle. We would have repeated the experiment to get a photo, but, we ran out of hydrogen peroxide.

Join us next time for Module 3 and The Atmosphere

Check out other Apologia Physical Science Labs HERE.