Activity

Write a secret message

In this activity, students use a UV light-emitting diode pen to write secret messages and investigate a range of objects to see if or how they fluoresce.

Invisible fluorescent ink under an UV light.

UV fluorescence

Information can be kept secret using invisible fluorescent ink that can only be seen under UV light.

Rights: The University of Waikato Te Whare Wānanga o Waikato

By the end of this activity, students should be able to:

  • explain why an invisible dye fluoresces when UVA shines on it

  • use UV light to investigate objects to see if and how they fluoresce.

Download the Word file (see link below) for:

  • introduction/background notes

  • what you need

  • what to do.

Published:29 July 2008