Hi all! We recently had a unit in science about chemistry, and today I will do a reflection on everything I have taken away from it.
In the unit, we performed several experiments that caused physical or chemical changes, and we had to identify them. For example, we had a reaction where magnesium ribbon held under a flame for a while, and the flaming end produced a really big spark for a while.
Here is a video of the reaction:
I learnt that there is a very big difference between physical and chemical changes. I first thought that they were basically the same thing. However, most chemical changes are irreversible, which was pretty obvious but yet I didn’t really realise until now. I also got to witness some other reactions such as elephant toothpaste and some explosions which I, unfortunately, do not have video footage of due to safety reasons.
I also learnt a lot about density and about the separation techniques. I always imagined that a device similar to the Separation Funnel existed but I finally got to use one and the experience was pretty different from what I was expecting. I was expecting some colour-sensing technology and it would just pour until the sensor didn’t sense anything of that colour. However, it’s just by hand. There’s no fancy technology.
Here is a video of the separation funnel in action:
I also learnt about the evaporation technique, and I never knew about this technique. I had never even imagined separating saltwater. But after learning about this technique, it just made a lot of sense and it was pretty much all reliant on logic and math, which I already knew would be the case for physics, I didn’t expect chemistry to be similarly closely related to math.