Expert Insights

I think it’s a key teaching topic, also because it’s teaching students to look at data and to interpret data, to assess which part of that data is going to get them to the answer and which part is exquisite detail that they can come back to later on. 

It’s continuous learning.  I mean, what I used to try to say to students when I taught the acid-base stuff I’d say ‘look there are only about six types of problems and if you can solve one of them you can solve them all because they’re all the same.’ But what you’ve got to be able to do is look at the question and say to yourself ‘this is one of those types of questions therefore this is the way I should think about approaching it.’  So take the question, dissect it, decide what you’re being asked to do, decide what information you’re given, and then say ‘yeah that’s one of those types of questions, this is the way I should go about solving it.'  If you can get that across to them, that it’s not a new universe every time you get a question, it’s simply a repeat universe of the same type of question... But many students tend to look at each problem as a new universe and start from the beginning again.  Many students don’t see that there is a limited number of problems that can be asked on a certain topic.

Ions and ionic chemistry are essential to life and just about everything they will run across.

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.

Difficulties are having to relearn something that they thought was true from school and not understanding the evolving nature of science. New knowledge is easier to assimilate than changing old knowledge.

It is vitally important for their understanding of chemistry that they understand that molecules are three-dimensional things and that they have a spatial requirement in that they have a shape of their own and that shape will change.  They can't do higher level manipulations without an understanding of three-dimensional nature of molecules.

So, it’s helping to bed down analysis, problem solving, doing the sort of detective work to get to an answer.  And the students also seem to quite enjoy having material presented to them in that way - here’s a spectrum, what do you think the structure is, because it’s a more active form of learning as well.  So I find I enjoy teaching it, and they respond well in terms of, they keep coming in and asking me for additional problems to practise on which is clearly evidence that they feel it’s challenging them.

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.

I remember when I was taught this, that the only definition we were given was Le Chatelier’s actual definition, or his principle, and I remember reading that language and going geez, that’s really hard to follow as a student, so I used to always try and present that and then break it down in to a more simple sort of version that I thought would be easier to understand.

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.

Pages