Introduction
Junior Cycle Science helps students understand the natural world and how scientific knowledge is developed. It builds scientific literacy through investigation, communication, evidence and reflection across biology, chemistry, physics and earth-and-space contexts.
Students do practical work, study issues in science and learn to ask good questions about data, claims and explanations. It creates a strong foundation for later science learning while remaining closely connected to everyday life.
Current marking structure and 2027 onwards
Current marking structure
Junior Cycle Science includes two Classroom-Based Assessments: Extended experimental investigation (EEI) and Science in society investigation (SSI). The Assessment Task linked to the second Classroom-Based Assessment is allocated 10% of the marks used to determine the SEC grade, and the final common-level examination is the remaining state-certified component.
2027 onwards
As of May 24, 2026, Curriculum Online has not published a confirmed 2027 replacement specification for the current Junior Cycle Science course. Consultation and development material exists, but the current specification remains the official published course.
Contents of the course
The official specification lists five strands across pages 16-20 of the Junior Cycle Science specification:
Strand one: The nature of science
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- 1. Appreciate how scientists work and how scientific ideas are modified over time.
- 2. Recognise questions that are appropriate for scientific investigation, pose testable hypotheses, and evaluate and compare strategies for investigating hypotheses.
- 3. Design, plan and conduct investigations, considering reliability, accuracy, precision, fairness, safety, ethics and suitable equipment.
- 4. Produce, select and critically analyse data to identify patterns, relationships and anomalous observations, then draw and justify conclusions.
- 5. Review and reflect on the skills and thinking used in investigations, and apply learning to unfamiliar contexts.
- 6. Conduct research relevant to a scientific issue and evaluate sources of information, including secondary data.
- 7. Organise and communicate research and investigative findings in ways suited to purpose and audience.
- 8. Evaluate media-based arguments concerning science and technology.
- 9. Research and present information on scientists' contribution to discovery and invention, and its impact on society.
- 10. Appreciate the role of science in society, its personal, social and global importance, and how society influences scientific research.
Strand two: Earth and space
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- 1. Describe relationships between celestial objects including moons, asteroids, comets, planets, stars, solar systems, galaxies and space.
- 2. Explore a scientific model to illustrate the origin of the universe.
- 3. Interpret data to compare Earth with other planets and moons in the solar system.
- 4. Develop and use a model of the Earth-Sun-Moon system to describe seasons, lunar phases and eclipses.
- 5. Describe the cycling of matter, including carbon and water, and associate it with biological and atmospheric phenomena.
- 6. Research different energy sources and communicate an informed view of how current and future energy needs on Earth can be met.
- 7. Illustrate how Earth processes and human factors influence climate, and evaluate climate-change effects and responses.
- 8. Examine hazards and benefits of space exploration and discuss its future role and implications in society.
Strand three: Chemical world
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- 1. Investigate whether mass is unchanged when chemical and physical changes take place.
- 2. Develop and use models to describe the atomic nature of matter and account for conservation of mass, changes of state, physical change, chemical change, mixtures and separation.
- 3. Describe and model atomic structure in terms of nucleus, protons, neutrons and electrons, comparing their mass and charge.
- 4. Classify substances as elements, compounds, mixtures, metals, non-metals, solids, liquids, gases and solutions.
- 5. Use the Periodic Table to predict the ratio of atoms in compounds of two elements.
- 6. Investigate properties of materials including solubility, conductivity, melting points and boiling points.
- 7. Investigate variables affecting rates of chemical reactions, including production of common gases and biochemical reactions.
- 8. Investigate reactions between acids and bases, using indicators and the pH scale.
- 9. Consider chemical reactions in terms of energy, using exothermic, endothermic and activation energy, and simple energy profile diagrams.
- 10. Evaluate how humans contribute to sustainability through extraction, use, disposal and recycling of materials.
Strand four: Physical world
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- 1. Select and use appropriate measuring instruments.
- 2. Identify and measure or calculate length, mass, time, temperature, area, volume, density, speed, acceleration, force, potential difference, current, resistance and electrical power.
- 3. Investigate patterns and relationships between physical observables.
- 4. Research and discuss a technological application of physics in terms of scientific, societal and environmental impact.
- 5. Design and build simple electronic circuits.
- 6. Explain energy conservation and analyse processes in terms of energy changes and dissipation.
- 7. Design, build and test a device that transforms energy from one form to another, describing energy changes and ways to improve efficiency.
- 8. Research and discuss ethical and sustainability issues from the generation and consumption of electricity.
Strand five: Biological world
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- 1. Investigate animal and plant cell structures and relate them to their functions.
- 2. Describe asexual and sexual reproduction, and explore inheritance and variation of genetically controlled characteristics.
- 3. Outline evolution by natural selection and how it explains diversity of living things.
- 4. Describe the structure, function and interactions of the digestive, circulatory and respiratory systems.
- 5. Conduct a habitat study and investigate adaptation, competition and interdependence within habitats and communities.
- 6. Evaluate how human health is affected by inherited factors and environmental factors, including nutrition and lifestyle choices, and examine micro-organisms in human health.
- 7. Describe respiration and photosynthesis as chemical and biological processes, and investigate factors that affect them.
- 8. Explain how matter and energy flow through ecosystems.
- 9. Explain human sexual reproduction and discuss medical, ethical and societal issues.
- 10. Evaluate how humans can conserve ecological biodiversity and contribute to global food production, appreciating ecosystem benefits.
Zr Academy offers Junior Cycle Science support in Dublin 2 and online for students who want stronger experiments, clearer explanations and a better foundation for senior-cycle science.
