Lesson plan

Forensics: The Honey Mystery 2 (Ink chromatography)

Summary
In the second lesson of the Honey Mystery, students narrow down the suspects further with evidence in a written note. An adjacent lesson uses ink chromatography to create abstract art.
Science content
Chemistry: Physical Changes, Solutions, Mixtures and Separating (2, 4, 5, 6)
Materials
  • Remaining suspects from the previous lesson (The Honey Mystery 1): black and brown bear, black cat, black and white cat
  • three informant stuffies, only one a cat, one a bear, any colours
  • three black pens and a note written with one of them, in the posession of the the three informant stuffies
  • coffee filters
  • washable coloured ink pens (dark colours often work best)
  • small tubs of water
  • Q-tips
Procedure

Reintroduce the remaining suspects from the previous lesson (The Honey Mystery 1)
It should be the back and white cat, the black and brown bear and the black cat.

Dramatize a note being brought to you:
Since I saw you last, I received some interesting news. This envelope was hand delivered by three very small, scared animals (show stuffies). They threw me the note, then ran away.
“My sister was so hungry. It was she that stole the honey from Pooh”.
If we can figure out who wrote the note, maybe it will help us figure out who stole the honey.
I called them back and asked them to tell me more, but all they would do is hand over their pens.

We will do a technique called chromatography to figure out who wrote the note.
This technique is used by scientists to separate the colours in inks from a pen, or to separate the colours in lipstick or paint found at a crime scene.
Do first activity (Chromatography with ink pens (black) and ink on a note).

(In our lesson it was the spotty cat that wrote the note, so her cousin, also a cat, stole the honey. This eliminates any bear suspects, and leaves the two cats as suspects).

We can also use chromatography to make some amazing patterns.
Do an art activity with chromatography of coloured pens.

Follow this lesson with The Honey Mystery 3.

Grades taught
Gr K
Gr 1
Gr 4
Gr 5
Teaching Site
Gordon Elementary
ingridscience afterschool