We've learned about invisible ink this week! First of all, we used lemon juice to write secret messages to our friends. We left them to dry while we went on a treasure hunt. We had to hunt around to find hidden messages written in highlighter on black paper. We used a black light torch to read the messages. The fluorescent ink from the highlighters glowed under the black light.
We played with colour changing felt tip pens. We used the clear pen to draw a picture then used the other colours over the top. When they touched the clear pen, they changed colour! We remembered from our chromatography last week that ink is made up of lots of different colours. The clear pen hides some of the pigments and leaves others behind, creating the effect of a changing colour!
Here are some links for ways you can make invisible ink at home:
- Do all colour highlighters glow under a black light?
- Does other citrus fruit juices work as invisible ink?
- Can you write an invisible message with a white crayon and watercolour paint? How does that work?
This week, we learned about chromatography. We used coffee filter paper to separate the different coloured inks in our felt tip pens. They made a rainbow - especially the black pen! We also investigated different types of black pen and we discovered that they all had different ink compositions!
Here are some links explaining the experiment and how you can adapt it at home:
- What colours did you see?
- Which had the most colours?
- Did it link to colour mixing?
- Does it work with all types of pen? (e.g. permanent marker, biro, felt tip pen, whiteboard pen?)
Today we learned about dissolving. We made a pattern with Skittles and predicted what might happen when we poured water on them. We thought the Skittles might melt or the paper plate might burn. However, we found out that they made a wonderful pattern as the sugar shell dissolved. We then tested M&Ms and the same thing happened! This time, the chocolate melted too but the 'M' did not dissolve. Smarties dissolved quickly too. Then we tested Skittles with no shell. They did dissolve but it was a lot slower.
Here are some links explaining the experiment and how you can adapt it at home (and use it to help you pray):
- Is cold water faster or slower than hot water?
- What happens if you use another liquid?
- Does fizzy water work the same?
- Can you think of any other sweets that would do the same?