Junior Cycle Science: the 2027 exam, the CBAs, grades and practice questions

The Junior Cycle Science exam in 2027

The exam's length and common level are in the NCCA specification: you respond in writing to stimulus material, and each year's paper samples the learning outcomes. The 2027 changes are in the Assessment Arrangements 2027: no Assessment Task, no change to the written exam, and at least one CBA per student. The 2027 dates aren't out yet (as of 7 November 2026); in 2026 the Junior Cycle written exams ran from 3 to 15 June (Department of Education and Youth).

The Junior Cycle Science CBAs

• CBA 1, the extended experimental investigation (end of second year): over three weeks you form a hypothesis, plan and carry out an experiment, analyse your data and reflect on the process.
• CBA 2, the science in society investigation (third year): over three weeks you research a socio-scientific issue, evaluate the claims and opinions, and draw evidence-based conclusions.

What Junior Cycle Science covers

• Nature of science (the unifying strand): how science works, investigating, and science in society.
• Earth and space: the solar system, the Earth Sun Moon system (seasons, lunar phases, eclipses) and the carbon and water cycles.
• Chemical world: the composition and properties of matter, and the changes it undergoes.
• Physical world: measuring quantities such as density, speed and current, forces, and energy.
• Biological world: cells, living things and how they interact with each other and the environment.

Grades since 2025 (gov.ie): Distinction 85% or more, Higher Merit 70 to under 85, Merit 55 to under 70, Achieved 40 to under 55, Partially Achieved 20 to under 40, and Not Graded under 20.

Junior Cycle Science practice questions

We wrote these for this guide, one from each contextual strand.

Question 1 (Physical world): a metal block of mass 54 g takes up 20 cm³. What is its density? Answer: density = mass ÷ volume = 54 ÷ 20 = 2.7 g/cm³. Try other values in the Density Calculator.

Question 2 (Chemical world): marble chips react with acid, giving off 48 cm³ of gas in the first 12 s. Find the mean rate of reaction. Answer: mean rate = volume of gas ÷ time = 48 ÷ 12 = 4 cm³/s. Using smaller chips or warmer acid would make it faster. Work out a mean rate in our Reaction Kinetics course and press Mark.

Question 3 (Biological world): write the word equation for photosynthesis. Answer: carbon dioxide + water → glucose + oxygen, using light energy absorbed by chlorophyll.

Question 4 (Earth and space): why does Ireland have warm summers and cold winters? Answer: the Earth's axis is tilted. In June the northern hemisphere tilts towards the Sun, so days are longer and sunlight strikes more directly. In December it tilts away. It isn't because the Earth is closer to the Sun in summer.

Common mistakes

• Skipping the stimulus material. Questions are built on the information given, so read it carefully.
• Missing units on calculated answers, such as g/cm³.
• Explaining seasons by distance from the Sun instead of the tilt.
• Mixing up the particles in an atom: protons are positive, electrons negative and neutrons neutral.

Use a daily paper as a short timed mock

There are daily papers for third year and first and second year science, plus single-subject papers in physics, chemistry and biology. Between them they cover atoms and reactions, cells, ecology, forces, electricity, waves and energy. The third-year paper also includes momentum, quantitative chemistry and organic chemistry, which go beyond the Junior Cycle specification, and none of the papers covers Earth and space in depth. For when mocks happen, see our Junior Cycle mocks guide.

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