Chemistry - Invisible inks

In this MEL Academy lesson your children will:

  • learn the nature of signs of chemical reactions
  • discover how heating effects reactions
  • make invisible inks with their own hands

Lesson time

5:00am   PST (San Francisco, Seattle, ...)
6:00am   MST (Phoenix, Denver, ...)
7:00am   CST (Chicago, Houston, ...)
8:00am   EST (New York, Toronto, ...)
1:00pm   GMT (London, ...)

Lesson duration: 45-55 minutes.

Prepare in advance

In this lesson, we will conduct "Invisible inks" DIY experiments. Prepare in advance household materials shown below.

DIY Materials

  lemon juice or lime juice
  7x White paper
  6 small glasses/cups
  UV / Blacklight (optional)
  washing powder (optional)
  red grape juice baking soda milk access to water


Please, download and print this worksheet in advance. You’ll need to refer to it during the lesson.

MEL Experiment

If you are a subscriber of MEL Chemistry then you can conduct Invisible copper experiment from the Chemystry of spies chemistry set:

Chemistry for spies


This lesson is presented by Katie Moon:

Katie Moon

Hi, I'm Katie! I am a secondary school science teacher and general space nerd. I studied astrophysics at Sheffield University before embarking on a PGCE at Bristol University. That was in 2016. Since then I have taught in the UK and around the world before settling down with my laptop as a full-time online tutor in 2018. I am a firm believer that practicals are the best way to learn important concepts in science. So if you want a teacher who simply loves science (all of it, not just space!), who loves experiments and who oozes enthusiasm then you're in the right place!