Imagining New Elements

The current semester isn’t even over yet, and I’m already excited about my classes for next semester! There could be several reasons: (1) I’ve been thinking about how student learning can be improved in my classes. (2) The bookstore has been harassing me for over a month with automated e-mails to select textbooks for next semester. (3) We’re currently in Registration Madness, and so I’m having many conversations with students about classes next semester. It’s likely a combination of all three factors, and more that I can’t think of at the moment. That’s because my mind space is being occupied by a great idea I’ve had this week!

So I was trying to come up with a theme that would tie the majority of first-semester General Chemistry together, that might culminate in a creative final project for students, and I might have hit on something interesting! (Or at least, I’m stoked about it right this minute!) While you’re waiting with bated breath to hear this miraculous idea, let me wax poetic with some context and history. I started this blog almost 1.5 years ago in preparation for my Spring 2015 second-semester General Chemistry class. Part of the reason was that I wanted students to blog about connections between what they were learning in class, and anything else they found interesting. The theme that semester was Energy (which fit in nicely with the main topics covered – thermodynamics, kinetics, and equilibria). I was hoping this would culminate in a creative final project related to Energy – but I was over-ambitious with all the new things I was introducing in class that I decided to axe it after a mid-semester survey. (The students thought the current workload was too demanding – they might have been right this time.)

But now I’m excited about taking another run at a creative final project for first-year students. What a great start it could be to their college experience! (Yes, I know I sound idealistic – but you need a dose of idealism to be excited about your job every day. My colleagues, in general, will describe me as exceedingly pragmatic.) What might tie the topics that we cover in General Chemistry 1? A peek at my syllabus (not necessarily in order) suggests:

·      Atomic Structure

·      Nuclear Chemistry

·      Electronic Structure of Atoms

·      The Periodic Table

·      Chemical Bonding and Molecular Structure

·      States of Matter and Properties

·      Intermolecular Forces

·      Chemical Reactions and Stoichiometry

Here’s my idea for the final creative project: Imagine you could create a new element (as Tony Stark does in Iron Man 2). What properties would be desirable in this new element and why? How would it be different from the properties of current elements in our known universe? (Be detailed at the level of atomic and molecular structure!) How would it interact chemically with current elements in our periodic table? If your new element formed compounds, what properties would they have? (Anticipate those that may not be on your original list of desired properties.) Finally (and this might be difficult), how might you create such a new element? (You can imagine advanced technology that allows you to manipulate matter in different ways.)

That was the gist of it. I need to do some refining to this rough idea. To explore how this might play out, maybe I am interested in diversifying carbon-based life (okay, that’s a big one). In an earlier post, I sort of touched this area via a quick imaginary analysis by imagining the different range of diversity if there was no carbon, nitrogen, oxygen, fluorine (i.e., in the opposite direction – this would probably reduce diversity). So let’s start with the simple idea that to get more diverse molecules you want a new element like carbon, except that it can form up to five strong chemical bonds rather than four. Perhaps it should be a nitrogen analog (five valence electrons) but prefers not to have a lone pair. I think we’d want it still to have the electronegativity of carbon so that it could form strong non-polar bonds with hydrogen, and strong polar bonds with other electronegative elements. Let’s call it quintogen for now – the substance that generates molecules and macromolecular structures with five strong bonds.

Quintogen would form a lattice structure different from carbon’s diamond. The five bonds may make it a super-hard substance, and therefore it could cut diamond. There might not be a good analogue to graphite however since it is unclear if one would get the resonance stabilization of an equivalent hexagonal benzene ring. If each quintogen formed four bonds with an additional electron to delocalize, the molecule would not be flat and extended in two-dimensions. But if partial orbital overlap at different angles are sufficient, maybe it would have a diamond-like lattice that is conductive – aha! Perhaps there is an allotrope as hard as diamond but with conductive abilities. What if you had three bonds (hexagonally shaped) and two unpaired electrons. There could be a benzene like structure if the additional electron was not a fermion but a boson (so as not to be killed by the Pauli exclusion principle), but now this gets the student into much less familiar territory.

This suggests that the parameters may need to be more constrained so that students relate these properties to concepts they should learn in General Chemistry. Maybe the new element must have atoms that contain a nucleus and electrons. The nuclear particles could be more exotic (partly because there is much about nuclear structure that is still unknown). I’d personally have to learn a little more in this area. I know something about shell structures, quarks, the strong and weak nuclear forces, and I certainly teach students about the “belt of stability” for non-radioactive isotopes.

Would quintogen scavenge oxygen from the atmosphere? Quintogen monoxide would be reactive. Quintogen dioxide probably has a net dipole and therefore higher melting and boiling points – might it be a liquid at room temperature? Hydroquintogens (the analogue to hydrocarbons) could release more energy upon combustion. There is so much room to speculate – and maybe students will think very hard about the underlying concepts of atomic and molecular structure, and how that impacts chemical bonding and reactivity. Interestingly this speculation is a form of Alchemy. You don’t often see the word alchemy in chemistry journals but the computational chemists (my tribe) seem at least to have acknowledged that we do this. A Google search will lead you to applications structure-based drug design and searching for new superhard materials. This perhaps fits in very well with my typical first day of class featuring the Alchemists!

(More speculation to come as I refine this train of thought.)