IB Physics Syllabus Changes: What Students Need to Know About the 2025 Course

The changes at a glance

Most of the physics itself is familiar. What changed is how the course is organised and how it is assessed.

Where the familiar topics went

The five themes are A, space, time and motion; B, the particulate nature of matter; C, wave behaviour; D, fields; and E, nuclear and quantum physics. Most old core topics map onto one theme, but a few moved in ways that surprise students.

Electric current and circuits now sit in theme B with thermal physics, rather than alongside fields. Several ideas that used to be optional are now part of the HL course within the themes, including rigid body mechanics and special relativity, while stellar physics appears in theme E. Some old option content is no longer examined at all.

• Theme A: kinematics, forces and momentum, work, energy and power, plus HL rigid body mechanics and relativity.
• Theme B: thermal energy, the greenhouse effect, gas laws, and current and circuits, plus HL thermodynamics.
• Theme C: simple harmonic motion, wave models and phenomena, standing waves, and the Doppler effect.
• Theme D: gravitational, electric, and magnetic fields, plus HL electromagnetic induction.
• Theme E: atomic structure, radioactive decay, fission, and stars, plus HL quantum physics.

The exam papers now

There are two written papers. Paper 1 is split into section 1A, multiple-choice questions, and section 1B, data-based questions built around experimental scenarios. Paper 2 contains short-answer and extended-response questions from across all five themes, often combining more than one theme in a single question.

At SL, Paper 1 lasts 1 hour 30 minutes and Paper 2 lasts 1 hour 30 minutes. At HL they last 2 hours and 2 hours 30 minutes. Paper 1 is worth 36% and Paper 2 44% at both levels, with the internal assessment making up the remaining 20%.

The practical effect is that experimental skills are examined in the written papers, not just in the internal assessment. Students who treated lab work as separate from exam revision are the most exposed.

The new internal assessment

The internal assessment is still a scientific investigation worth 20%, but it is marked against four equally weighted criteria: research design, data analysis, conclusion, and evaluation, each out of 6. The report has a maximum of 3,000 words.

The separate criteria for personal engagement and communication have gone, so marks now depend more directly on the quality of the method, the processing of data and uncertainties, and an honest evaluation of the investigation's limits.

Can you still use old past papers?

Yes, with care. Questions on shared content, such as mechanics, thermal physics, waves, fields, and nuclear physics, remain excellent practice. Old Paper 3 and option questions should be skipped unless the topic now sits within a theme.

What old papers cannot provide is practice in the new formats: Paper 1B data questions and Paper 2 questions that deliberately link themes. Students should mix older questions for content with the newer specimen and recent papers for format.

• Use old Paper 1 and Paper 2 questions for topics that appear in the current themes.
• Skip old option and Paper 3 questions unless the content moved into a theme.
• Practise Paper 1B-style data questions from current materials regularly, not just before exams.
• Include questions that combine themes, such as energy in fields or circuits with thermal effects.

What this means for revision

The redesign rewards students who understand connections and practical method rather than those who memorise topic by topic. Revision should include mixed-theme questions, regular graph and uncertainty practice, and written explanations, not only calculations.

For families considering support, the key question for a tutor is whether they have taught the current course. A tutor working from the old syllabus may spend time on content that is no longer examined and too little on Paper 1B.