Year 10 science questions with answers: biology, chemistry, physics, and Earth and space

Each daily paper has 8 original questions worth 25 to 35 marks. Each practises one strand and also has topics from Year 9 or from senior courses; the strand sections below say which questions to sit. The mixed Year 10 Science paper fits in its inheritance and evolution, forces and rates questions, but much of the rest is Year 11 and 12 work. No paper covers climate change, so use the question on this page.

What's in Year 10 science

These make up the Science understanding strand; Science as a human endeavour and Science inquiry run through all of them. In NSW, Year 10 moves to the Science 7 to 10 Syllabus (2023) in 2027 under the Department of Education's plan, with Years 7 and 9 starting in 2026. There is no state-wide Year 10 science exam: your school sets its own. Year 10 is the base for Year 11 Biology, Chemistry and Physics.

We wrote the questions below for this page. Try each one before you read the answer.

Year 10 science biology: heredity and evolution

The daily Year 10 Science: Biology paper fits in its genetics and inheritance, cell division and evolution questions. Its homeostasis, nervous system, circulation, digestion and immunity questions revise Year 9 body systems; skip its limiting factors and respiration questions.

1. A test cross. In pea plants, tall (T) is dominant to short (t). A tall plant of unknown genotype is crossed with a short plant, and about half the offspring are short. What was the tall plant's genotype? Answer: the short parent is tt and can only pass on t. Short offspring (tt) need a t from the tall parent too, so the tall plant must be Tt. The Punnett square gives 2 Tt (tall) and 2 tt (short): a 1:1 ratio. If the tall plant were TT, every offspring would be tall.

Try a probability question on a cross in our Genetics and DNA course, then press Mark. The Genetics Cross Calculator draws Punnett squares for any cross.

2. Mitosis and meiosis. Give two differences between them. Answer: mitosis makes two cells genetically identical to the parent, with the full set of chromosomes, for growth and repair. Meiosis makes four cells with half the chromosomes, each genetically different, to form sex cells (gametes).

3. Natural selection. A farmer sprays a paddock with the same weedkiller every year, and after a few years it barely works. Use natural selection to explain why. Answer: the weeds vary, and by chance a few carry an allele that lets them survive the spray. Spraying kills the rest: a selection pressure. The survivors set seed and pass the allele on, so each year a larger share of the weeds carries it, until most of the population survives the spray. Simulate it with the Natural Selection simulator.

Year 10 science chemistry: the periodic table and reactions

The daily Year 10 Science: Chemistry paper fits in its atomic structure, bonding, energy changes and rates and collision theory questions. Skip moles, titration, organic chemistry, electrolysis and equilibrium, which come in Year 11 and 12.

4. Trends in the periodic table. Why does reactivity increase down group 1, from lithium to potassium? Answer: all group 1 atoms have one outer electron. Going down, each atom has an extra shell, so that single electron sits further out, with more inner electrons shielding it. The nucleus holds it less tightly, it is lost more easily, and the metal reacts more readily.

5. Displacement and rates. A strip of zinc goes into blue copper(II) sulfate solution. What happens, and why does zinc powder react faster than a strip? Answer: zinc is more reactive than copper, so it displaces it: Zn + CuSO₄ → ZnSO₄ + Cu. Pink-brown copper forms and the blue colour fades. Grinding zinc to powder exposes far more of its atoms to the solution (a larger surface area), so successful collisions are more frequent and the reaction speeds up. Higher temperature, higher concentration and a catalyst also speed reactions up.

Year 10 science physics: Newton's laws

The daily Year 10 Science: Physics paper fits in its Newton's laws and momentum and stopping distance questions, and its space physics questions support the big bang. Its waves, radioactivity and energy questions revise Year 9; skip its circuits, mains electricity and electromagnetism questions.

6. Force, mass and acceleration. A 1200 kg car has a resultant forward force of 3000 N. What is its acceleration? Then explain, with Newton's third law, what pushes the car forward. Answer: F = ma, so a = 3000 ÷ 1200 = 2.5 m/s². The tyres push backward on the road, and the road pushes forward on the tyres with an equal and opposite force: that forward push accelerates the car.

Earth and space science: the big bang and climate change

7. Evidence for the big bang. Describe two observations that support the big bang theory. Answer: light from distant galaxies is redshifted, and galaxies at greater distances show bigger redshifts, so the universe is expanding from a hotter, denser past. The cosmic microwave background is faint radiation coming from every direction, left over from when the young universe cooled enough to let light travel freely. Our Big Bang course covers both.

8. Global climate change. Using energy flow between Earth's spheres, explain why adding carbon dioxide to the atmosphere warms the planet. Answer: incoming sunlight, mostly visible light, reaches and heats the land and sea, which in turn emit infrared. Carbon dioxide absorbs some of that infrared and re-radiates it, much of it back toward the surface. With extra carbon dioxide, outgoing energy falls below incoming energy, so the oceans, land and air warm until the two flows match again at a higher temperature.

Use the daily papers as a practice test

1. Pick the paper for the strand you are revising and work to the suggested time, about 35 to 40 minutes.
2. Skip the questions from other years listed in that strand's section above.
3. Write the equation, the numbers with units, and the answer with its unit.
4. Mark it, note which strand each lost mark belongs to, and use the big bang and climate change questions here for Earth and space science.

Common Year 10 science mistakes

• Confusing genotype and phenotype. Tt is a genotype; tall is the phenotype.
• Saying weeds become resistant because they need to. The resistance was already there by chance; the antibiotic selects it.
• Using the driving force in F = ma instead of the resultant force after friction and drag.
• Putting Newton's third law pairs on the same object. The two forces act on different objects.
• Saying the big bang was an explosion into space. Space itself has been expanding everywhere.

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