Expert Insights

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.

I want them to get the big picture about what analytical chemistry is about in terms of solving an analytical chemistry problem.  They need to know the big picture rather than just focussing on the measurement step.

A lot of it is from colleagues.  Conferences are fantastic.  You know, your chemical education conferences.  I do go to a lot of those.

Chemistry is a different language so I try to approach it that way by explaining the ideas behind symbols.

So you shouldn’t be rigid, you shouldn’t be rigid in what you’re going to do.  It’s always stunned me that people say you should know where you start a lecture and where you’re going to finish, and if you get to that point and you finish ten minutes early you then should just finish.  I’ve never worked on that principle.  I never know where I’m going to start because I never know where I’m going to finish, right.  So where I finished the lecture before is where I start the next day, I haven’t got a set content.  If a student asks me an interesting question and I get the feeling that they want to know that answer I’ll go off for five or ten minutes or three or four minutes answering it, and if I don’t get to the end of where I thought I was going to get to, too bad I’ll do it next time.  So you go with the flow, you don’t go with a rigid thing ‘I’ve got to get through these 15 slides today and if I don’t the world will end,’ because it won’t.

The culture in the chemistry department was always lots and lots of content.  And that’s changed now because you don’t need it, because they can find it another way, but you’ve got to give them the framework to understand the content.

The big picture is that in any topic there’re key principles, and if you as a lecturer can get across the key principles, that then sets them up to solve problems and to think about the other principles and how they connect.  But if they don’t, if they’re not prepared to accept the fact that there are these key principles you need to understand then it’s not going to work.

Students see equations and panic. Students struggle to transfer mathematical knowledge to chemical situations. Students silo knowledge and find it hard to relate concepts to actual systems.

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.

But if you’re honest, they’ll be honest right.  And I think that’s really important. If you b*gger something up and you really do make a blue or even a little blue, tell them.  Say ‘oh look this was wrong, you know this is what it should be’.  So that’s important - to be honest, to be upfront.  Recognise that we’re dealing, in 2015 or 2014, we’re dealing with OP1 to maybe 14. Recognise the breadth of that class. Don’t teach the top, don’t teach the bottom, teach somewhere in the middle, but try to make sure that you don’t lose the top ones and lose the bottom ones, which is very difficult to do and you only do it with experience.

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