The actual curly arrow mechanisms are in a way themselves cartoons, how they map to the reality in the way that a Micky Mouse might map to real life.
Expert Insights
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Ions and ionic chemistry are essential to life and just about everything they will run across. |
I think to get the students to straight away mark for somebody else what they’ve just done and then to mark or take part in the marking of two other versions of the same thing is really powerful. So it’s not so much me directly finding out what they do and don’t understand but using methods by which they can diagnose for themselves. I haven’t got this, she has, or yep I have got most of that, she hasn’t, and I can see where she went wrong. Very powerful, very powerful indeed. |
You could identify people and you use it in a constructive way. But if you could show some identity, that you’re not a remote person up the front, that the big class is not anonymous, it just helps to break down that barrier. And once they trust you and once they like coming, that solves a lot of other problems - behavioural problems, learning problems and so on. |
We do an awful lot of focus on teaching but realisticly, authentic assessment that actually engages the student, that’s a tougher ask... I set a lot of essay type assignments. I think we ought to do more of that in science. But when I started doing this I used to get very poor results and it’s taken me a little while to realise that the students weren’t understanding what the questions was. They didn’t understand what I meant by compare and contrast or discuss or argue for this. So increasingly now I use workshops to actually spend time with the students unpacking, what is this essay assignment about? What am I actually asking you to do? What do you need to think about? And not assuming that they know how to write an essay. |
When you think of things in terms of energy you can represent energy … energy can be modelled as a particle, as matter. It can be modelled using waves and then trying to talk about how we would use each model as it's appropriate for a particular situation. It's the sort of things we observe might dictate which model we use to explain it, by recognising that in each case there is another model but perhaps just not as useful. So maybe it goes back to just trying to show that everything that we do is a model, every model has its upside and its downside and that we usually only use a model that’s as detailed as it needs to be for the particular concept that you're trying to get across. If you want to get across a concept of a car to someone who has never seen a car you don't probably show them a Ferrari or a drag racing car. Maybe you show them a Lego style block and we do the same thing with our scientific models as well. I guess trying to get across that idea that this is the model that we're going to use but it can be a lot more complicated. I don't want you to think it's as simple as this but it's appropriate under the circumstance. So I guess I spend a lot of time talking about things as models when I'm talking about quantum mechanics. Our treatment in the first year, which is where I cover it, a little bit of second year but I don't take a mathematical detail treatment of quantum mechanics. Someone else does that, so I really bow to them. So most of mine is non-mathematical, just simple mathematics and mainly conceptual type of stuff. I guess some of the things I try and do to illustrate the differences between the models and the way that we use them is to ask questions in class that might be postulated in such a way that you can't answer it if you're thinking about both models at the same time. So the one I like is where I show say a 2s orbital and the probability distribution of that node in between. I talk about things that … there's one briefly, this plum pudding model which they all laugh about. When you look at this 2s model there is a probability and a high probability, relatively so, that the electron can be inside the nucleus, if you think about it in particle terms. Then talk about the nodes and so on and how they arise in quantum mechanics and so on and then ask questions like if the electron can be here and here but it can never be here how does it get there? ... I try and get across maybe the bigger picture, everything we're going to do from this point on (because we do this fairly early in first year) - everything is going to be a model. Nothing is going to be right. Nothing is going to be wrong. Nothing is going to be exactly the way it is. Everything will be just a model. You'll hear us saying things like ‘this is how it is’ or ‘this is what's happening’. But really you need to interpret that as ‘this is a model and this is how this model is used to explain this particular phenomenon. |
So I think we just, I used to give them, perhaps, 10 minutes to work on a problem, now I probably only give them two or three minutes. I find that concentrates them and prevents them just talking about the State of Origin or whatever it is that’s on their mind. We just need to keep changing the activity, rather than have extended activities... we want them to chat, but I think human beings won’t sit and chat about quantum mechanics for more than two or three minutes, they’ll get onto what they want for lunch. So it’s that balance. |
This understanding builds students' knowledge about the basic structure of matter which stimulates them to think in sub-microscopic level that provides the fundamental understanding for further chemistry learning. |
So into the lectures I put kind of ad breaks, I suppose, short 'meet the scientist' breaks. So we would have a photograph and fun facts about a scientist and various places we would have a stop, and I have told them that all of that information wasn't on the exam, so they knew that they could stop and just take a breather and then pick back up on the chemistry afterwards. So that, I think helped, especially the ones that were just finding it all a bit kind of overwhelming. |
It was a revelation to me in second year when [one of the top professors] said to me, "Buy a model kit." And so now I tell all my students. |