Chemistry workshop: pH indicators

Impressions of Simon’s monthly science workshop with John Maas, from Wednesday this week. The main topic was the pH value, acids and bases. We used red cabbage water as a pH indicator – it still smells bad in the apartment!














Simon draws series and parallel circuits with conductive paint

Simon loves the conductive paint. After we finished making the Bare Conductive Voltage Village kit (previous post), he made two circuits, parallel and series, on his own without and help on my behalf. He did use weak AAA batteries first, so it didn’t work. When I told him he should switch to the 9V batteries, his circuits started to shine!


This is Simon’s parallel circuit:


And this is a series circuit:


RaspberryPi work station

When Simon got a new RaspberryPi 3 from Sinterklaas on Sunday joy quickly turned into drama as he discovered the old (and only) keyboard we had at home was outdated and had no usb connection. His original plan was to use the television screen as the RaspberryPi screen and that would have let towards constant struggle with those other members of the family who actually wanted to watch tv. What made things worse was that it was Sunday and all Belgian computer stores (and all other Belgian stores) were closed. Simon was devastated as he’d really set his mind on this project. We jumped in the car and drove to The Netherlands where people never stop working and neither does MediaMarkt. Within an hour we got a wireless keyboard and a nice Samsung screen, both at a good price, and went for a drink on the Grote Markt square of the old Dutch town Bergen op Zoom. And now we’ve got one more “desktop”.

Simon has been using this single board computer to train html and JavaScript. His favourite is setting the background colour in hexadecimals.




Ohm’s Law Applied to Lemons

Simon wrote a poster with electricity formulas (from memory) this morning and applied one of them (Ohm’s law) to his advanced lemon experiment.



We had already tried this experiment before but one lemon did not light an LED. Simon’s become more of an expert this time around. He used not one but 4 lemons now and measured the voltage (in Volts) and the current (in Amperes).


And he employed his sister as assistant.


The four lemons gave us almost 4 Volts!




Simon used his voltage and current measurements to determine the resistance:



He then decided that 24 Ohms was too little and added a resistor to his lemon circuit:


But with a resistor the LED light did not light up – apparently the voltage became too low. After all, the voltage is the resistance times the current. I suggested Simon try it again without the resistor, with the almost 4 Volts the lemons made. And it worked!


PiTop, day 2 (Tuesday)

Didn’t really feel like going to his first Fench class this morning. All he wanted to do before and after French class was program:

We were utterly shattered when at the end of day two the PiTop stopped working. First it froze and we had to force reboot it by pressing the on/off button. This may have caused corruption of the MicroSD. The PiTop’s power does go on but the screen remains grey. Simon was crying bitterly at first but started looking for rebooting solutions on YouTube later in the evening. He is planning to reimage the SD-card tomorrow. Even if that doesn’t help there is a lot of learning involved in the process I believe. I have also written a letter to the PiTop support team.

Simon’s invention idea

Simon told me today he invented a new electronics kit that would allow him to “make” any misical instrument he wanted. Outside at the playground he indulged in listing all the parts he needed for the kit and I couldn’t help but film that:

He later added that he forgot to mention the SparkFun RedBoard and the soldering iron.