Mad About Science Week – Emily Pringle
The next stop on our week-long tour was Hamilton Middle School in the Denver Public Schools to shine the spotlight on Ms. Emily Pringle, science teacher extraordinaire. Emily Pringle has taught there for eight years and uses the scientific method to make the light bulbs come on in her bright, young eager students. She and the kids showed us her candle lab experiment, also known as the “composition of air” demonstration. Here’s the concept… A candle sits in the bottom of a dish full of colored water. The candle is lighted and covered with a test tube or jar. When the candle burns out (because of the lack of oxygen), the water rises in the test tube. Data is gathered as to the volume of water that displaces the air in the tube. Ms. Pringle’s class concluded from the experiment that 21% of the air that we breathe is oxygen (and the students are correct!). Read more.
Video: On Day 4 of Mad Scientist Week Steve Spangler visits an enlightened science class at Hamilton Middle School. 6 a.m. October 6, 2005.
Well they are either very smart children, or Mrs Pringle is indeed a genius.
This lab has an error. The candle flame goes out because the oxygen has been used and is combined with carbon creating CO2. This is not the only reason why the water level in the jar rises. The flame also heats the air in the container causing it to expand. That is why you will observe bubbles of air being pushed out the bottom of the jar.