Expert Insights

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.

Students from high school might understand that vinegar for example is a weak acid compared to hydrochloric acid, but they never knew why. And you could then show them that with equilibrium, this is why. And all of a sudden they’re, 'oh, I’ve always known that I shouldn’t spill HCL on my hand, but I can spill vinegar on my hand and put it on my fish and chips'... Those sorts of moments can really... the students go ‘oh wow.’

Anonymous

At the start of every class my standard thing was ‘can you see me, can you hear me, can you see the slide?’ I would always look up the back for someone to put their hand up and always I would never talk to the front row. I’d always talk middle and back row and if someone was talking in the back row I’d pick them up and say ‘hey you, be quiet’ and then they know that I’ve seen them.

So you’ve got to focus on the whole class not just the people at the front - the people at the back as well.  Because sometimes smart people sit at the back as well, not just the dummies who want to get out. You’ve got to make sure you know everyone in the class.  And the surprising thing is that most kids sit in the same place every lecture.

So you can actually recognise where they are and who they are.  You don’t know their names but there’s a pattern in the way they sit.  You’ve just got to be aware of that.  So the trick is to embrace the whole class with your - you know physically, just with your eyes and and the way you talk.  You know, when you wave your hands, wave it to the back row. Make sure they’re involved.

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.

I started lecturing before I did my Diploma of Education and I would have recommended to all of the lecturers to do it because it really helped me in my teaching.  Mind you, I already had a bit of experience, I don’t know, you know, the chicken or the egg type thing.

I think for a lot of people, before they started chemistry, especially if they haven't done any chemistry before, they've got no real understanding of the difference between macroscopic things and microscopic and atomic sized things. We all know how important that distinction is.

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. 

So the first thing that I really stress that people do, is that they actually go and watch some classes.  I think that’s the most important thing.  When they’re coming straight out of a post doc, or they’re coming straight out of the Research Centre, and then, they’re told they’re going to be lecturing 300 first year students, they’ve got to go and sit in the back of the lecture theatres for a few weeks.... when I came over from the UK to here, and the class sizes are about three or four times as big, it was just a real help to be able to see what worked and didn’t work  – how little time the students were on task in quite a few lectures.  Where the lecturer would just be talking and be oblivious to this.  I think people just learn a lot by seeing good things, but they also learn a lot by seeing quite bad things going on.

I changed my method of teaching to be a team-based learning approach where in fact as teams they are responsible to each other within the team for their level of engagement or for what they put into that team and if they don’t put in what the team thinks is useful then they get marked on that, their peers mark them on how much they’re contributing to the team’s goals.  So rather than me as the educator saying you need to do this and you need to do that, in fact the system is such that as a team they’re responsible for a certain outcome and the team must achieve that outcome and so they need to work together.  For the students who don’t put in as much as the team expects of them then there is peer pressure to increase their level of input and their engagement and if the students don’t then the team members get a chance to reflect upon that and give them a sort of team work score.

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

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