Simon is seriously enjoying his new Molymod chemistry modeling sets and has been obsessing about which set contains what atoms and bonds.
Hurray! We have just built 7,333333333333 x 10^-9 of the human DNA:
Some like the football, Simon plays with the buckyball, or Buckminsterfullerine, made up of 60 carbon atoms:
Simon is baking Dutch traditional “pepernootjes” (“pepper nuts” or spicy cookies) and explains why they get bigger in size after you put them in the oven and what the optimal tiling pattern is to fit a maximal number of cookies on the baking sheet.
Want some me sugar in your tea?
Simon built this sucrose (table sugar) molecule with the help of Theodore Gray’s Molecules book (although he is pretty sure there is a mistake in the Dutch version of the book, on a different page, where the fructose, glucose and galactose molecular structures seem to be mixed up – the sucrose description helped him discover this as the table sugar molecule is made up of one fructose and one glucose molecule).
Simon is also fascinated how sugar and salt, substances that are easy to confuse on the kitchen table, are made of molecules that are so “wildly different”:
Simon really wanted to try building a capillary bowl – a version of a perpetual motion machine in which water circulates. Although aware of the fact that perpetual motion was not possible, he is keen on seeing it for himself. Off we were to the hardware store where we got some funnels and hoses. What we observed was Pascal’s law in action: the level of water evened out and there was no way to get the water rise higher at one end of the hose than at the other and thus no way to get the water flow into the funnel.
Eventually, we did manage to get the capillary bowl to work for a split second when we filled it with coke and beer. The pressure of water is higher than that of foam, because liquid has a higher density than foam. We used alcohol free beer, so there wasn’t that much foam.
Our new MEL Chemistry box arrived, containing tons of color fun! We have already tried two experiments. In the Color changing milk experiment, the soap touches the milk creating a very thin film of soap on the milk’s surface and causing the colors to spread along with it, producing a mesmerising effect. Molecules of soap and other similar substances lower the surface tension of different liquids and thus are called surface-active agents (SAA). Simon took it a notch further and created antibubbles that glide on the film of soap:
We thought this one looked like a nuclear explosion:
The second experiment we did was called Magic Liquid and felt like performing a magic trick: a yellowish liquid poured in five different cups turned five different colors, almost all the colors of the rainbow! The secret was putting a tiny bit of a different chemical substance on the bottom of every cup beforehand. The yellowish stuff was actually Thymol blue, also known as thymolsulfonephthalein (chemical formula C27H30O5S ), a pH indicator, and changed color according the acidity of the substances that were already in the cups. The larger the quantity of protons H+, the higher the acidity of the medium, while the OH– ions are responsible for the basic medium:
Thymol blue molecule visible on the iPad screen:
We also checked the pH of the substances using indicator standard teststrips:
The pH rainbow:
Simon had already been busy with colors for a few days, revisiting his Magformers collection to build this gorgeous color wheel:
We later repeated the MEL Science demos for Simon and Neva precocious friend:
Simon went further on his research about what exactly valence is, and what determines how many other atoms an atom can bond with. “What about Helium? My question is, how many bonds does Helium have?” I hear him ask and watch as he searches the internet for a chemical bonds table. “From this table, I can see that the amount of bonds is not equal to the amount of electrons in the last orbital, the amount of valence electrons!” But what is the algorithm to calculate the valence of every element? He then discovered that the information about it hides inside the periodic table where elements are divided into groups. But those groups are more about the number of the valence electrons.” Mom, it says 7 for chlorine, but in my Chemistry modeling set chlorine has just one hole!” Something didn’t add up. I suggested we look into Theodore Gray’s Molecules book, which we only have in Dutch. There we studied the drawings of the outer layers of the “schil” of different atoms (in Dutch, the orbital cloud is called “schil”, which is the same as the peel of an apple). And all of a sudden, Simon knew it. He started shaking, his body stiffened with excitement. He realized that the element’s valence is the number of electrons the outer orbital can take minus the number it already has! That is, the number of “holes”, of vacancies! What a feast it was to see how he made this huge discovery all on his own, how he physically felt the discovery strike his mind and pierce his body like an envigorating wave, and how now he owned that knowledge, something he was genuinely interested in and something he experienced so deeply.
What Simon did then was grab ping-pong balls and little atoms from his modeling set and invite me and Neva to play with him, as if we were the unhappy elements that missed electrons in our outer shells and we started exchanging our ping-pong balls (our electrons) to form happy and complete molecules. And then he took two balls and gave two balls to me and said: “I don’t need you. I’m Helium and happy alone”, a big smile on his face at he made the joke.
Here we pretend we are two oxygen atoms trying to form a molecule. The white balls are how many valence electrons each of us has.
Making atom models from clay together with sis. The blue clay balls are electrons and the red ones are protons.
Simon has been down with a serious flu for the past three days and yet, the moment he started feeling just a little more alive he resumed his learning: following Physics Girl and Veritasium tutorials, reading up on valence quarks and the bonds between elements. And as soon as the fever was gone, he started sharing what he learned with me again (on fluid dynamics and turbulent and laminar boundaries, on quantum spin and entanglement) the old enthusiastic Simon was back!
Our third MEL Science box arrived back in August, when we were on vacation. We have already tried two experiments from the box, both perhaps more suitable for winter. Instant Snow, using sodium polyacrylate (the stuff you can find in diapers):
And growing salt crystals on a paper Christmas tree:
Above: “Mom, look, this is what we breathe in and this is what we breathe out!”
Looking for a better organic chemistry set now, with plenty of carbon and hydrogen pieces. Any tips?
Today we opened our second MEL Chemistry box with two experiments using tin (Sn). We made a tin dendrite and grew a tin hedgehog. Both experiments involved preparing a tin chloride SnCl2 solution (by mixing tin chloride with a sodium bisulfate). In the first experiment, we had electric current flow through the solution (by connecting it to batteries via crocodile clips), so it acted like an electrolyte. A tin reduction reaction took place: Sn2+(solution) + 2e–→ Sn(solid)
The tin dendrite grows in the direction that the electric current flows through the solution; from one clip towards the other:
In the second experiment, we simply dropped a piece of zinc into the tin chloride solution. What happened as a result was a substitution reaction: some zinc dissolved into the solution, while tin precipitated on the surface of the zinc pellet in the form of lovely needles:
SnCl2 + Zn → Sn + ZnCl2