CBT for Chemistry

Concept-based learning is applied across all parts of an IB education, so if you have taught MYP you will be familiar with the ideas. As DP courses are reviewed and updated, all DP subjects will incorporate this concept-based philosophy.

The important thing to recognise is that you will have taught many aspects of the course conceptually without realising and you should therefore have confidence in your learning experiences. Concept-based learning is not new to us as chemistry teachers!

When Nature of Science was released nine years ago, we initially wondered how we were going to bring it into our classes. We then went away, reflected, re-read the statements and realised that the IB had formalised something that we had been doing for years anyway. The same argument holds true with concept-based learning, so there is no need to throw away your good resources and start again. Much of the course material you have used in the past you will be able to reuse and repurpose to fit the new course.

So, what is concept-based learning?

Imagine a visual representation of teaching DP chemistry looks like this:

Only when all of the topics are put together and combined do they start to make sense. As stand-alone topics, some aspects do not quite ‘work’. For example, can you really understand the SN2 mechanism (organic) if you do not understand the concept of the rate-determining step (kinetic)? Or can you understand why benzene organic does not react with addition reactions like an alkene (organic) if you do not understand about delocalised π electrons (bonding)?

As a teacher, you may well have taught the kinetics topic and told the students that “In a month or two, we will learn how this affects an organic chemistry reaction”. In concept-based learning, instead of teaching the idea in a couple of months, you are able to teach it immediately.

Are these concepts assessed? Or do they just need to be applied?

The subject content in the guide is useful in this respect. The guide contains the information that will be assessed. For example, the concept of electron pairs sharing reactions will not be expressly assessed, but the content that this relates to will be assessed (for example, nucleophilic substitution reactions).

The current examination papers have always been set up with conceptual questions. It is not possible to look at a question and say “that is assessing periodicity”. Concepts are integrated and many topics can be assessed within the same question. It is not yet known if the IB will use its own terminology in the questions for the first examination in May 2025 (for example, “This question is about electron sharing reactions”).

What are the concepts for chemistry?

The IB has outlined two broad concepts for chemistry:

Structure and Reactivity.

In each concept there are a number of themes, for example, models of bonding in the structure concept, or how much, how fast, and how far in the reactivity concept. Each theme itself has a number of sub-themes, for example, the amount of chemical change, the rate of chemical change and the extent of chemical change are all sub-themes in the how much, how fast, and how far reactivity theme. The subthemes are akin to layers of increasingly more specific content. The following diagram provides a nice summary of the concepts around ‘change’ as a visual example.

All of the structure and reactivity themes and contexts can be seen in the roadmap (below) that is also found in the IBDP Chemistry Guide (FA 2025) p.25:

The students can be taught the themes in any order that you wish. The Teacher Support Material (TSM) provides different models to navigate the syllabus content. One of these models is based on the old (legacy) course, but as the IB has spent time developing the new road map and new concepts, it would probably be advisable to test the new models.

The conceptual approach requires you to use and develop your own linking questions. Some example linking questions are included in the guide (don’t confuse this with guiding questions!).

A successful conceptual approach also requires you to fully embrace the Nature of Science (NoS) components. These components have been radically reduced to make them more manageable and they have shaped the new guide and the conceptual approach. Ignore them at your peril! It is expected that more NoS ‘type’ examination questions will be used in paper 1B, such as ‘evaluate a hypothesis’ or ‘deduce the observations’.

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