Sparking Interest in STEM

Faculty from the Department of Chemistry presented demonstrations and information as part of the nearby Tama County Family STEM Festival 2016, held on April 3. This outreach event used interactive activities to introduce children and parents to careers in science, technology, engineering, and math (STEM). Grinnell College's representatives engaged the public with several demonstrations. 

 

Erick Leggans ’05, assistant professor of chemistry, demonstrated the density of invisible gasses by pouring carbon dioxide into a container with lit candles. The candles need oxygen in our air to keep burning. If the carbon dioxide is lighter than oxygen in the air, the candles will stay lit, but if the carbon dioxide is heavier than oxygen, it will sink to the space around the candles and they will go out. Observers could see for themselves what happened.

 

Blown-up balloons and liquid nitrogen, which is extremely cold, were used by Cori Ortiz, assistant professor of chemistry, to show how volume is related to temperature. This relationship is known as Charles' Law, named after the scientist who came up with the formula in the late 1700s. 

 

In the activities led by Elaine Marzluff, professor of chemistry, color was used as an indicator to test the pH of liquids. Being able to see a change in color is also helpful for knowing when chemical reactions change the acidity of liquids. Red cabbage was used as the indicator to test different liquids such as water and juice. In one experiment, dry ice was added to tap water to observe a change in pH. 

 

The demonstrations chosen by the chemistry faculty for this festival were intended to be accessible concepts for young minds and to get them thinking about science in everyday experiences.