Of Cabbages and Chemistry
Written by Jacqueline Barber
The humble cabbage has noble chemical merit. The juice from
red cabbage turns pink when mixed with an acid, turns green
when mixed with a base, and remains purple when mixed with a
neutral substance. What a chemical canvas!
In this series of engaging activities, students use the special
indicator properties of red cabbage juice to investigate acids
and bases. Rather than starting with standard definitions, this
unit plunges children into experiments through which they discover
for themselves the distinction between the two, and their relationship
to "neutral." The "Presto Change-O" activity
reveals that acids and bases are parts of a continuum. Students
also learn that chemicals can be grouped by behaviors, and these
activities provide a great example of how closely chemistry
connects to daily life. In a special assessment activity, students
use their newfound knowledge to play a game in which they try
to protect friendly visitors from outer space, who can only
survive in a neutral environment.
Time: Four 60-minute or eight 30-minute sessions plus follow-up
Comment on this GEMS unit.
Spanish Language Student Materials
What materials are needed to present this unit? See the full list.