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Friday, July 31, 2015

STEM Series: Exploding SG50 Fireworks and Wobbly Jellyfish

STEM activities are all the rage now. Stemming (excuse the pun) from an interagency meeting at the National Science Foundation, the term has implications for how the subjects which the acronym stands for (Science, Technology, Engineering and Mathematics) are taught in school and what this means for technological advancement and the jobs of the future.

We've been dabbling in some Science activities on the homeschool front. First of all, because it adds a good mix to the daily Literacy and Numeracy activities that we do. Secondly, because I have two Science-loving boys who love to see the cause and effect that happens in a Science experiment - they are always asking "why" and seeking to understand the reasons for how things work. And lastly, because we all think that they're super fun!
Our jellyfish in an ocean!
Oh, yes, how we love Science experiments!
Today, we tried out some exploding fireworks in a jar. Singapore's 50th Jubilee celebration is happening next week, and I thought we should launch our celebratory week in anticipation of the fireworks that will happen in the special SG5o parade. However, I also saw a jellyfish in a jar craft activity which looked like something our ocean-loving 3-year-old might appreciate, so I decided to combine the two activities this morning.

The Science concept behind the exploding fireworks is simple - the denser liquid tends to sink, and the less dense liquid will float. We observed a few teaspoonfuls of vegetable oil before adding a few drops of food colouring to it. The boys got to hypothesise whether the oil or the food colouring would float when we poured the mixture into some warm water in a jar. They looked at the tiny droplets of oil forming on the surface of the liquid in the bowl. 
Mixing the vegetable oil and food colouring
Lastly, we poured the mixture into a bowl filled with two-thirds of warm water, and they watched with fascination as the "fireworks" of food colouring began to dissolve in the water while a layer of oil formed at the surface. Voila! Our very own National Day fireworks, without having to go to the parade.
SG50 fireworks in a bottle!
Observing the layer of oil settling on top of the surface of the water.
For the jellyfish jar, we used some of the same oil and food colouring mixture we had gotten once the fireworks subsided, thinning it so that the water in the jar would be more translucent than opaque. 

We made the wobbly jellyfish by taking an old plastic bag and drawing concentric circles on it with Sharpie markers (you can use any permanent marker for this). Arrange the circle part of the bag over a small cup, pour a bit of water into the cavity and quickly pull it up to form a small pocket of water. Tie this up and you get your jellyfish head. Use a pair of scissors to trim the rest of the bag into long tentacles.
Draw layers of concentric circles in the centre of the plastic bag. These form the head of the jellyfish.
Fill it with water and tie it with some string to make a little water balloon.
Cutting the tentacles of the jellyfish
Place your jellyfish, some shells, and plastic sea creatures of your choice into the jar with the coloured water, seal it with some tape, and enjoy the smiles your children will give you when they see their tiny ocean in a jar! The jellyfish bobbing around actually is a really calming and soothing one. I would use this as a sensory tube as well.

Our ocean in a bottle! E had fun turning it upside down and watching the shells and jellyfish float.
This makes for a perfect sensory bottle. You can use it to help your kids calm down and relax! 

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