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## National STEM Learning Centre

Skip to 0 minutes and 7 seconds MARK LANGLEY: Right, so if we’re going to start off with atoms, compounds, and mixtures as a topic in the 11 to 14 range, so what are the key bits of this, the key components and ideas that we actually need to have across here?

Skip to 0 minutes and 21 seconds LOUISE: I was thinking, actually, it would really good to start with the atomic structure. So start on the very small, and we can always work outward, can’t we?

Skip to 0 minutes and 32 seconds MARK: So I suppose we also need, then, to move towards the particle model, because it’s something they’ll have come across before in primary level education, isn’t it?

Skip to 0 minutes and 42 seconds LOUISE: Mm-hmm, so the particle model.

Skip to 0 minutes and 44 seconds MARK: The particle model, yeah, or particle theory, I suppose.

Skip to 0 minutes and 49 seconds LOUISE: Yes, interesting one to unpick as well.

Skip to 0 minutes and 53 seconds MARK: Yeah, where are we on next?

Skip to 0 minutes and 57 seconds LOUISE: Well, I think once We’ve looked at our particles and what they’re made of, we’re going to have to start looking at what happens when we join them together. So maybe moving into our naming of compounds.

Skip to 1 minute and 5 seconds MARK: Yep, that sounds like a good idea.

Skip to 1 minute and 13 seconds I suppose the mixture part as well, that brings in some of the separation, doesn’t it, and actually separate the mixtures out and separating them.

Skip to 1 minute and 20 seconds LOUISE: Yeah, that’s a real key idea, isn’t it, in understanding what a mixture is.

Skip to 1 minute and 23 seconds MARK: And there’s also quite a few practical techniques that we’ll have to be putting out there as well.

Skip to 1 minute and 26 seconds LOUISE: Yeah, so separating mixtures.

Skip to 1 minute and 35 seconds And then there’s the issue of do we bring in the periodic table now or later? What’s your feeling on that?

Skip to 1 minute and 41 seconds MARK: Well, I suppose as we’re trying to do the name and the compounds and the structure, it’s possibly worth bringing in now.

Skip to 1 minute and 49 seconds MARK: I say, well, we can put it down now, and see if it fits ino otherwise, we can always make sure it’s in the parallel topics that go with it. So yeah, we’ll put it in for now.

Skip to 1 minute and 57 seconds LOUISE: Yeah, because you’ve got to know what we’re using in there, yeah.

Skip to 1 minute and 59 seconds MARK: We’ll put it in for now.

Skip to 2 minutes and 5 seconds So let’s just take the first one there that we’ve got– atomic structure– so what you intend the students to learn about this idea. So what’s the key things we need from atomic structure?

Skip to 2 minutes and 17 seconds LOUISE: So we’re going to have to get them to have some idea, some model of what it looks like. So are we talking about one where we’ve got the nucleus? Do we need to move on much further from that?

Skip to 2 minutes and 30 seconds MARK: I think we need to get up to the nuclear model at this part without going into too much more detail, because we’re not expecting them to go beyond, really, knowing and understanding that an atom has got a nucleus, which is the heavy part and it’s got electrons around the outside. The nucleus is positive. The electrons are negative. And I think that’s where we need to be at this stage before we start getting too much further.

Skip to 2 minutes and 53 seconds LOUISE: Yeah, otherwise we’re going to go beyond where we need to be. So how will you know that students have learnt this? So what assessment activities are we’re going to use?

Skip to 3 minutes and 9 seconds MARK: I think a key part of this one, I don’t know if you agree. It’s about the modelling, actually getting them to physically make models to show that they understand what it looks like and to be able to sort of compare different models. different types of atom.

Skip to 3 minutes and 23 seconds LOUISE: So we want them to be able to model.

Skip to 3 minutes and 30 seconds Any key questions we think we need to–

Skip to 3 minutes and 33 seconds MARK: Maybe name the key part. So being able to name the nucleus and point out where the electrons are. I think there’s a question for later in seeing how it relates to the physics specification as to whether we start bringing in about the protons and neutrons at this stage. But I think, we’ll identify the key parts later then, are you OK with that?

Skip to 3 minutes and 55 seconds MARK: OK, so why is it important for students to know this? What’s the point? Where do we go from here?

Skip to 4 minutes and 2 seconds LOUISE: Yeah, so we need them to have a clear idea of the model, because that’s going to impact on some of the other things we’re looking at. Do we need them to know that they’re mainly empty space?

Skip to 4 minutes and 17 seconds MARK: I think so. I think that’s one of the interesting things that always makes it interesting for students when they realise the most of an atom is absolutely nothing. And so it’s trying to address, again, some of the misconceptions later, but it’s also getting them to think very carefully about what the properties of atoms are and why they do certain things.

Skip to 4 minutes and 35 seconds LOUISE: So we want to look at the properties. So you were picking up on something there that they do know something about it. So if we don’t correct that, we’re actually letting them go on with their misconceptions.

Skip to 4 minutes and 47 seconds MARK: Absolutely, absolutely, so we need to make sure they’ve got that clear understanding of, at this level, what we mean by an atomic model, the language we’re using.

Skip to 4 minutes and 58 seconds LOUISE: Absolutely. Right, so what else do you know about this idea that you do not intend students to know yet? So where are we going with this?

Skip to 5 minutes and 7 seconds MARK: Well, I think we’re– I mean, we’re not going really in-depth into the protons and neutrons We’re talking about the nucleus being the heavy part. Actually, that doesn’t link us, then, up to the periodic table because we’re going to need, at some point, to bring that in about the atomic mass, aren’t we? But we’re not really going to go into protons and neutrons just yet. So the subatomic particles, I think, we’re leaving till much later on.

Skip to 5 minutes and 29 seconds LOUISE: Right, so yes, the details about those subatomic particles.

Skip to 5 minutes and 36 seconds MARK: That’s where there’s something about electrons, isn’t there, as well– how much we want them to think about what electrons are doing. We’re not going to come to the all Chemistry is about electrons moving around in charge, yet, I think. So we’re going to have them look at electrons, but I don’t think it’s going to be very much about what they do, where they go.

Skip to 5 minutes and 54 seconds LOUISE: I suppose you want them to know where they are, because that’s important that they’re–

Skip to 6 minutes and 0 seconds MARK: But not necessarily that they’re sitting in energy levels or shells because that’s the next step in the model, isn’t it?

Skip to 6 minutes and 6 seconds LOUISE: Yes, so we might want them to be aware of the word “electron,” but we’re not going to go into electron shells at this stage.

Skip to 6 minutes and 14 seconds MARK: So now, we’re on to the difficulties and limitations connected with teaching this idea.

Skip to 6 minutes and 19 seconds LOUISE: So we brought in those misconceptions, those preconceived ideas that students see these models in real life in numerous occasions, so we need to be able to address that otherwise, they may have a model that isn’t the one we’re using.

Skip to 6 minutes and 34 seconds MARK: Yeah, absolutely, and I think one of the big things, as well, that we’re going to have to consider is size.

Skip to 6 minutes and 43 seconds LOUISE: Mm, that’s a tricky one, isn’t it?

Skip to 6 minutes and 45 seconds MARK: Yeah, so the idea that they’re so small we can’t see them. We’re going to have to bring that out somehow.

Skip to 6 minutes and 51 seconds LOUISE: And they may already have looked at things that are bigger than atoms and have no idea how those things relate together.

Skip to 6 minutes and 57 seconds MARK: So that’s something we can look at when we think about how we then– what activities we can use to try and address that type of one. OK, so keep this atomic structure. Let’s move on to the next bit. So knowledge about students’ thinking, including misconceptions which influences your teaching of this idea. So we’ve got some sort that idea of preconceptions, particularly about size, in there. Is there anything else that comes up with students?

Skip to 7 minutes and 25 seconds LOUISE: I mean, I think we’re going back to that empty space, again. I don’t think they’ve got any comprehension of that.

Skip to 7 minutes and 30 seconds MARK: No, and actually the fact that they’ve also seen so many different models– they’ll see things on TV that people talk about atoms or what they look like or they’re represented. All the atoms sit there. or sometimes, even, that they have smiley faces on them. So it’s those things that we might need to do. So yes, I think, again, it’s the size and the different models.

Skip to 7 minutes and 48 seconds LOUISE: Yeah, put my empty space on there. Right, so other factors that influence your teaching of this idea. We were talking about the size and saying about maybe biology is showing them cells, letting them have a look under microscopes at cells. So we’ve got to link to that.

Skip to 8 minutes and 11 seconds MARK: And we do and we’ve also got that issue in biology of the word “nucleus” being used in biology, which we use in a completely different format for talking about the nucleus of an atom and students assume that often, they’re the same size. They’re the same thing. And so it goes back to science, but we’ve definitely got those cross Curricular links into Biology in particular to have a look at.

Skip to 8 minutes and 35 seconds LOUISE: How much do physics at this age bring in ideas about the atom?

Skip to 8 minutes and 40 seconds MARK: They’re not going to bring in too many, apart from the applications of the particle model in terms of solids, liquids, and gases and densities and the densities of different phases. So I think we can stick with trying to, at this point, I think, making sure we pull apart the Biology misconceptions about nucleus and the size part. Right, so now, we’re onto teaching procedures and practicals and particular reasons for using these to engage with the idea. I think one of the ones we can think very much about is the scale, isn’t it? Trying to get the idea of size in.

Skip to 9 minutes and 15 seconds Especially going back to how– if they’ve looked and measured how big biological cells are, where do atoms, and where does the nucleus of an atom sit on that scale? So there’s going to be quite a lot of maths in there that we’re going to have to unpick that sort of facts, powers of 10 type.

Skip to 9 minutes and 30 seconds LOUISE: Yeah, we will have to have a link with the maths. So in terms of– I mean, it’s difficult at this stage to do practical because we can’t see. So we’re going to have to model what they look like, rather than rely on being able to do something that’s showing us what’s going on at that level.

Skip to 9 minutes and 47 seconds MARK: So like the Plasticine type models, we’re getting out and actually making the different models and seeing how they fit.

Skip to 9 minutes and 53 seconds LOUISE: Yes, absolutely. Maybe we can bring that empty space idea in as well using the scale of our models.

Skip to 10 minutes and 1 second MARK: Yeah, maybe we actually could take them outside to actually model things like, well, how big is an atom compared to how big the nucleus is? So that actually might be an interesting one. If the weather’s good and depending on where they sit when we look at the overall plan, then we might actually get them outside to do something.

Skip to 10 minutes and 17 seconds LOUISE: Some demos, yeah, that would be great.

# Using the PCK Framework

The PCK planning tool helps you to breaks each topic down into chunks and the key ideas that students need to know.

The video above is an illustration of how using such a planning tool in curriculum design can support discussions with colleagues about subject matter, and develop pedagogical content knowledge. We have captured such a discussion for one full section of the planning tool, but you may want to watch selected parts.

The first question to consider is: how will you find out if you are successful and the students’ level of understanding? This is not always a test!

Only then do you start adding in other aspects of teaching and learning, such as the common misconceptions, where learners might go next, why it’s important for them to know about the topic, what the typical difficulties are with this topic, and finally what activities can be used.

This process takes into account backwards design: you identify learning outcomes, then decide on how you will assess progress against those outcomes, then design activities which will enable young people to show progress. This is not ‘teaching to the test’, but ensuring that assessment is well thought out.

Completing a framework also brings in considerations of the best order to teach things. Are there specific mathematical demands that need to be taught? Does it rely on other scientific knowledge? This can help in the ordering of the whole curriculum, as well as within a particular topic. Looking at planning across the sciences, not just with each separate discipline of biology, chemistry or physics, is essential for students to be able to make effective links, rather than teaching in silos of knowledge.

Finally, a framework like this works very well if there is a specialist and non-specialist working together, as they can draw on each other’s experience. For example, what might be an obvious choice for a specialist might need some explanation for the non-specialist, and this can then be fed back into supporting notes for the curriculum.

In the next two weeks we will explore these considerations in more detail.

## Discuss with colleagues

Download a copy of the PCK Framework planning tool and share it with your colleagues in school. Discuss with them whether this could be a useful tool for collaborative curriculum design.