We got the opportunity to create a mini science lesson for a group of P6 pupils as part of our Science Elective this week. The topic was on acids and alkalies, so we came up with the idea to focus on chemical reactions and make a small-scale “volcanic eruption”. The children loved it! They were eager to see which acid would react best with bicarbonate of soda and chose their favourite combination to try out in the volcano model. The results varied from sluggish thick foam creeping down the sides to rapid jets reaching the ceiling- eliciting coos of delight from the avid 10 year olds.
Before the children were given the chance to pick their favourite “eruption”, we determined their prior knowledge on acids and alkalies and the use of litmus paper. We then introduced them to four unknown liquids and asked them to find out which were acids and which were alkalies. Having been to a station where they were identifying the pH of household objects, they were able to do this using the litmus paper and started investigating what each liquid could be. Discussing it within their groups whilst smelling and carefully analyzing each one, many of them were able to identify them correctly. This activity enabled them to use investigative as well as teamwork skills- and a few needed very little prompting from us.
After this, the children started adding bicarbonate of soda to each liquid to see if there was a reaction. Through questioning and the process of elimination, they discovered that bicarbonate of soda is, in fact, an alkali as it only reacted with the acidic liquids. It was fascinating to watch one girl’s expressions dawn with realization as she worked it out herself.
This activity with the children proved very rewarding, as it showed me the importance of using scientific language which many of them were eager to adopt as well as ensuring that I allowed time for them to observe, investigate and discover on their own without prompting or questioning too quickly, if at all!
I also enjoyed working as part of a team, coming up with ideas, risk assessing and fine-tuning the ‘practicalities’ of it together. We were able to identify weaknesses in areas and improve them for the next group of children which was invaluable. The best reaction came last when one child asked what would happen if we mixed the vinegar and lemon juice together with the bicarbonate of soda. Suffice it to say, we had to clean the ceiling with that one…
