Science Smarts: Guar gum slime fun
By PATTY ROOKS on August 7, 2021.
As I write my article this week, I am anticipating what the upcoming school year will look like and what students will be asking me for. Of course, I am always being asked to either “blow something up” (not safe!) or “make a mess.” Of course, I never want to disappoint, so I dug through my notes looking for some of my more popular activities and this one kept coming up as one of my favorites – I hope you enjoy it as well. By the way, it is messy. Let’s get started – outside perhaps! Remember to ask an adult before doing this experiment. Materials • Guar gum • Water • Measuring spoons • Measuring cups • Three large plastic bowls or buckets • Immersion blender (optional but useful) • Mixing spoon • Food colouring • Borax • Masking tape • Marker • Safety goggles Procedure Make a guar gum solution: • Label the bowl with the masking tape and marker. • Measure one litre (4 cups) of tap water into the bowl. • Add 10 mL (two teaspoons of guar gum to the water. BE CAREFUL as if you add it in too fast or in one lump it will not mix in well. Gently sprinkle it on top. • Stir this well. I like to use an immersion blender so it blends up nice and smooth. • Set aside for now. • Make the borax solution: • Using the masking tape and marker label this bowl and mark on it POISON so NO ONE drinks it. • Pour 500 mL (two cups) of water into a bowl. • Add three or four drops of food colouring to the water and stir well. • Measure two tablespoons (30 mL) of borax and pour into the water. Stir well. • Mix the two solutions together: • Measure 250 mL (one cup) of the guar gum solution into a clean bowl. • Add 30 mL (two tablespoons) of the borax solution. • Stir well. • Have fun! • Wash your hands when finished and NEVER eat slime. • When you are finished dispose of your slime in the waste bin. What is going on? Did you know that guar gum is a natural polymer? I know that sounds really scientific, but really is quite easy to find and the legume it comes from is used as feed in livestock. It is an amazing substance. As you observed, it thickens up really well, and rather quickly too! It is used in many things from food to cosmetics as it is much more powerful than common starches. You can find guar gum in everything from rubber cement to yogurt because it is so useful. In this experiment you also added the borax solution. It can be quite complex how borate ions bond and so for the purposes of this experiment, it helped produce the gel like slime that is so much fun to run through your fingers! Enjoy! Patty Rooks, Senior Scientific Consultant PRAXIS, “Connecting Science To The Community”. Contact Praxis at praxis@praxismh.ca, http://www.praxismh.ca, Tweet or follow us @PraxisMedHat, or friend us on Facebook. Address: #12 826 11 Street S. E., Medicine Hat, Alberta, T1A 1T7 Phone: 403.527.5365, email: praxis@praxismh.ca. 40-39
