The removal of the Options is certainly a big contributor to the reduction in the content of the course. However, some topics from each of the former four Options are now included in the main syllabus – for example the bonding triangle (Option A), biofuels (Option B), fuel cells (Option C) and separation techniques (Option D). This is by no means an exhaustive list, but makes the point that all students will now be exposed to the applications and global context of chemistry in a range of fields.

The syllabus content is now presented in two main themes, Structure and Reactivity.    Emphasis is placed on the wide use of models in the study of chemistry, with consideration of their limitations and how they continue to evolve. Reaction mechanisms are classified as only four types, all of which are defined in terms of sub-atomic particle behaviour. At first glance this may give the impression that the syllabus has been drastically changed, but in fact, it is an elegant and stream-lined presentation that reinforces the concept of reactivity depending on structure. 

Guiding Questions are a new feature of the syllabus, given at the start of each sub-topic. The questions are purposefully open-ended, lending themselves to increasingly detailed consideration as the understanding of the topic deepens. These questions may serve as openers for a topic, teasing out students’ prior knowledge, and perhaps helping to suggest a sequence of what will be covered. They could also be used as a tool for assessment, looking for increasing depth and breadth at different stages in the learning. In topics where there are additional Understandings for the Higher Level course, HL students will be able to give a more in-depth answer at the end of the unit. Guiding Questions should be re-visited at the end of each sub-topic as a useful tool for revision

At the top of the ‘syllabus roadmap’ given at the start of the 2025 subject guide is a new section known as ‘Skills in the study of chemistry’. This is not intended as a topic to be taught in isolation, but is more of a checklist of skills that students must acquire during the course. It replaces the ‘prescribed practicals’, (aka ‘mandatory labs’) of the 2016 curriculum, and clarifies the techniques, technology and mathematical scope that is expected within the course. This approach gives more flexibility to teachers as to how and when they teach a specific skill. For example, carrying out distillation is an expected technique, but whether this is included as part of the oxidation of alcohols or while considering the separation of a mixture of liquids or anywhere else, is completely open to choice.

Linking Questions are another important feature of the new course. They are given in many of the syllabus Understandings, where they show a link to a different but related sub-topic. The goal of Linking Questions is to help create networked understanding, including from Skills in the study of chemistry and with the NOS. They focus on the unifying concepts and patterns, sometimes including anomalies. They may also probe limitations of models and prompt consideration of the application of chemistry in a real-world context. Linking Questions are unlikely to be used as questions in examinations per se, but the related concepts are considered an essential part of the course for assessment.