Menu Close

Elf on the Science Shelf – Balloon Flinker and Invisible Ink

This is the fourth in a series of posts featuring science activities for your Elf on the Shelf. You can see the whole series here.

Thanksgiving has passed and that darn elf is back.  If you’re like me, it’s day 2 and you’re already out of ideas.  There is no reason that you the elf has to do all the work. Use the elf to give the kids a challenge AND keep them out of your hair for a few minutes.

Balloon Flinker

A flinker neither floats nor sinks but does both at the same time, hanging in mid air.  All you need is a helium balloon on a string and some instructions from your elf to get the kids busy creating their own flinker.

A flinker doesn’t fall to the ground and it doesn’t keep rising into the sky, rather a flinker just hangs in the middle. What can you attach to this floating balloon to turn it into a flinker?

Invisible Ink

All kids love secret messages.  This could be useful when they need a little reminding to clean their room or stop fighting with their siblings.  You can use any one of these 5 invisible ink recipes, but I recommend the milk and pencils method shown in the video below.

white paper
whole or 2% milk
cotton swab
sharpened pencil
sand paper

To write the message just dip the cotton swab in milk with some fat (whole or 2% works best) and write the message on white paper.  Once the milk dries the message will be completely invisible.  Leave it out next to the elf with a pencil, sand paper and this message:

I’ve left a message below just for you.  To reveal the note rub the pencil lead on sand paper so that graphite snows down on the paper, then rub it around to see the words.