Expert Insights

They struggle with the language of chemistry.  So we sort of need to teach them the process and how to work out how to do these things.  We know that their tendency is just to attempt to memorise reactions.  Whereas if we can teach them to derive … find out what the nucleophile and the electrophile is then all they have to do is draw a curly arrow from the nucleophile to the electrophile, rather than trying to work out what the reaction is itself. 

I guess what every educator deals with is needing to find out what preconceptions there are at the start of the unit and then correct those and then keep on top of those throughout the course.  For example I get students who use the word particle and the word droplet interchangeably. Whereas to an expert, a particle is something that is made of a solid material and a droplet is something that’s a liquid material.  Students use those interchangeably so they may be talking about a suspension of solid materials but then they use the word droplet because they think it’s interchangeable with the word particle. Or vice versa, they might be talking about an emulsion and they talk about particles where they should be talking about droplets.  So because they’ve heard these phrases before in first year... the importance of using exactly correct terminology hasn’t been reinforced.

In the lecture theatre the best strategy there, where you’re confronted by all the constraints of the lecture theatre, is to stop and do stuff with the students, walk around amongst them, see what they’re actually doing... And out of that you might go back and address some aspect of it and revisit it or something like that or you might point them to some tools to use to work out some other aspect.  So in the lecture theatre it’s very much for me a case of stopping and going and seeing what they’re doing and if you don’t then clearly you don’t know. 

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.

In the workshops, the workshop idea as we run them is that you are out and about and amongst the students all the time in those groups, seeing what’s going on in the groups, seeing how they’re answering their questions.  They have set questions on sheets that they work through in groups and the groups of three just get one set.  They’re all working on them together and you’re moving in and out and around among the groups and seeing how they’re going.  In that circumstance you can quickly, having looked at three or four of your eight different groups, figure out where a particular issue would be and then that can be addressed on the board, it can be addressed with models or something like that.

Students should [only] be limited by students' curiosity.

It always seems like we're starting from further behind than a lot of the other sciences are because they seem to know less about chemistry when they get here.  If I say ‘think of a famous physicist’ you probably already have thought of three.  Then you could go outside and ask someone to think of a famous physicist and they'd probably think of at least one of the same ones.  You do the same thing with biologists.  If I say to think of a famous chemist … that's within chemistry circles, we can't do it.  We can name one but you know if you go out there and say, ‘Who is this person?’ they've got no idea.  So for some reason … we've never … chemists have never been able to popularise our topic, our content.  We've never been able to make it exciting enough that someone who is not studying it still wants to know about it.  And so I do think we've got a bigger challenge, for whatever reason.  Maybe there's something about chemistry that makes it less enjoyable, I don’t know.  There's definitely been an ongoing issue for us that it's not … people just don't know anything about it... Most people know Einstein's theory of relativity.  You don't see that really in everyday, go, "There's the theory of relativity at work." Newton's Law, sure, you see those and you … but, yeah, everybody knows Einstein.  And a lot of … I'll call them lay people, I don't like the term, but non-science people, could probably give you a hand wave explanation of what the theory of relativity is about, which is a pretty abstract thing.  I mean, if we think of the equivalent types of things in chemistry that are that abstract, nobody has a clue.  We teach them in third year to the remaining hard core people that are left. 

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.

When we’re teaching ideas in chemistry, I liken it to hacking your way through a forest.  It’s all this detail.... and you can’t expect students to do the hard work of fighting your way through the forest or the jungle, unless they have a global view of where they’re going. What I mean by that is, the other factors that influence the way I teach intermolecular forces, is that I keep going back to applications in the real world.  How is it that geckos can crawl up a wall, and almost sit on the ceiling without falling off?  How is it they’re able to stay there with gluey legs or what?  But the interactions between their feet and the ceiling are just, how could they maximise the attractions between the molecules in their feet, and the molecules in the ceiling? So what I’m trying to do all the time is to show applications, powerful, interesting, hopefully, and engaging applications of the ideas that are important. So, for students to engage and to feel, ‘well this is worth hacking my way through the jungle of detail to be able to understand it’, is to zoom out and show them how this topic relates to all of the other topics.  It’s called scaffolding, and it’s a very, very important idea. So, the other factors are essentially the incredible number of other applications of this idea... that the power of an idea is its explanatory power, and when they can see just how important an idea is, in being able to explain all sorts of phenomena, they might be willing to care about it more.

We all spend a certain amount of our class time going through definitions and jargon and getting students up to speed with the basic area and now that’s material which I take out of the class and put online and let students read and understand that in their own time before they come to the class.

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