Exploring small doses
In this activity, students explore small doses in the order of parts per million. They dilute food colouring to help them understand how small one part per million actually is.
By the end of this activity, students should be able to:
make a liquid measure of one part per million
recall the meaning of the term part per million (ppm)
explain the relationship between ppm and ppb
explain that small concentrations can be in substances without being visible
explain the importance of being accurate when making measurements in science.
Paracelsus (1493–1541)
Over 400 years ago, alchemist and physician Paracelsus said: “All substances are poisons; there is none that is not a poison. The right dose differentiates a poison from a remedy.”
Download the Word file (see link below) for:
introduction/background notes
what you need
what to do
student handout.
