Questions, Hypotheses and Models: a skill companion
A small set of reusable sheets that grow one inquiry skill at Year 10 depth: turning a relationship into an investigable question, a hypothesis with a reason and a prediction that could turn out wrong, and then using the result to choose between models and refine them. Print the scaffolds once and slot them into the science lessons you already teach.
What a skill companion is
Inquiry skills are not a topic of their own. They grow inside the units a class teaches all year, from heredity to reaction rates. So this pack is not a full term of lessons. It is three reusable scaffolds, a map of where they fit, and a short stand-alone lesson for teaching the skill on its own first.
Start here: five minutes
- Read the pairing map on the next page: it gives a hypothesis, a prediction and a model for each Year 10 topic.
- Print the two-models sheet when a class has data that two explanations could fit, and the hypothesis sheet when it plans a test.
- Cut out the cards once. They are reused all year.
- Open the free interactive unit on your board when you want a worked example of the skill.
- Run the one-page mini-lesson first if you want to teach the skill before folding it into a topic.
The step up from Year 9
The descriptor is the same in Years 9 and 10; the depth is not. In Year 9 students built a model from a pattern and checked its shape. In Year 10 they write hypotheses that make numerical predictions, say in advance which result would show them wrong, and use a test to decide between two competing models, then refine the better one when neither fits exactly.
Slot the skill into your science lessons
Every Year 10 topic has a relationship a class can test. This map gives one for each unit: a hypothesis with its reason, a prediction that could fail, and the model the test puts at risk.
| When you teach | The relationship | Hypothesis, with its reason | A prediction that could fail | The model at risk |
|---|---|---|---|---|
| Heredity: Cell Division and Inheritance (AC9S10U01) | Parents’ alleles and offspring traits | If two Tt plants are crossed, about three in four offspring are tall, because each parent passes on one allele at random | About 75 of 100 seedlings tall | Mendelian inheritance: the Punnett square |
| Evolution by Natural Selection (AC9S10U02) | Colour and survival | If a background is dark, dark paper “beetles” survive a class of hunting “birds” better, because they are found last | After three rounds, dark beetles are more than half | Natural selection |
| The Big Bang and the Universe (AC9S10U03) | Distance apart and speed apart | If the balloon is blown up, dots twice as far apart move apart twice as far, because the whole surface stretches | A ruler shows distances growing in proportion | An expanding universe |
| Energy Flow and Climate Change (AC9S10U04) | Carbon dioxide and warming | If a bottle holds more carbon dioxide, it warms faster under a lamp, because the gas absorbs infrared | The carbon dioxide bottle ends a few degrees warmer | The greenhouse effect |
| Newton’s Laws of Motion (AC9S10U05) | Mass and acceleration | If the mass doubles at the same force, the acceleration halves, because a = F ÷ m | 0.5, 1 and 2 kg give 4, 2 and 1 m/s² at 2 N | Newton’s second law |
| Atomic Structure and the Periodic Table (AC9S10U06) | Position in Group 1 and reactivity | If an element is lower in Group 1, it reacts faster with water, because its outer electron is further from the nucleus | Video of lithium, sodium and potassium: faster each time | Electron shells |
| Reaction Types and Rates (AC9S10U07) | Temperature and rate | If the acid is warmer, the reaction is faster by about the same factor for each 10-degree rise, because more collisions succeed | Gas in 30 s multiplies by about the same factor each step | Collision theory |
The three moves, and the picture that backs each one
When you want a worked example on the board, open the interactive unit and use the picture that matches the move.
- Ask a question with one variable changed: “Frame the question: change only the temperature”.
- Let the data choose between models: “See the relationship between temperature and rate” as a line graph.
- Tell a hypothesis from a guess: “Hypothesis or just a guess?”.
Two models fit the data. Which one predicts?
When two models both seem to fit, make each one predict something the other does not, then test it. Here, magnesium ribbon reacts with dilute acid at five temperatures. Build both models from the first 4 results and see which predicts the fifth.
| Acid temperature (°C) | 10 | 20 | 30 | 40 | 50 |
| Gas in 30 s (mL) | 9 | 15 | 24 | 38 | ? |
| Added each step | — | +6 | |||
| Multiplied each step | — | ×1.67 |
The first step is done for you. Fill the other steps from the first 4 results only.
A. Model A: each rise of 10 degrees adds about the same volume
B. Model B: each rise of 10 degrees multiplies the volume by about the same factor
C. The test
Your teacher gives the fifth result.
A hypothesis that could turn out wrong
A useful hypothesis names the relationship, gives a reason from a model, and makes a prediction precise enough to fail. Before the test, write down the result that would show it wrong. The first is done for you.
1. Newton’s Laws of Motion
| Investigable question | At a fixed pulling force of 2 N, how does the mass of a trolley affect its acceleration? |
|---|---|
| Independent and dependent variables | the mass of the trolley (kg); its acceleration (m/s²) |
| Hypothesis: if ... then ..., because ... | If the mass doubles, the acceleration halves, because a = F ÷ m: the same force shared by twice the mass. |
| Prediction, with numbers where you can | 0.5 kg: 4 m/s²; 1 kg: 2 m/s²; 2 kg: 1 m/s². |
| The result that would show it wrong | Doubling the mass barely changes the acceleration. |
2. Energy Flow and Climate Change
| Investigable question | Does a bottle of air with extra carbon dioxide warm faster under a lamp than a bottle of ordinary air? |
|---|---|
| Independent and dependent variables | |
| Hypothesis: if ... then ..., because ... | |
| Prediction, with numbers where you can | |
| The result that would show it wrong |
3. Reaction Types and Rates
| Investigable question | How does the size of marble chips affect how fast they react with dilute acid? |
|---|---|
| Independent and dependent variables | |
| Hypothesis: if ... then ..., because ... | |
| Prediction, with numbers where you can | |
| The result that would show it wrong |
Teacher note: a prediction that cannot fail (“something will change”) tests nothing. Ask for a direction, a size or a shape, and the result that would count against it.
Which result would show each hypothesis wrong?
Cut out the twelve cards. Six are hypotheses from the Year 10 topics; six are results. Pair each hypothesis with the one result that would count against it. Then, for any pair, say what else could explain that result before you throw the hypothesis out.
Teacher note: the answer sheet lists the pairs. A result that goes against a hypothesis is a reason to check the method, then to revise the model.
Two models, one helicopter
A paper helicopter, two cut rotor blades folded apart with a paper clip at the base, spins as it falls. Does a longer blade make it fall more slowly? Two models disagree. Model 1: a longer blade pushes on more air, so the helicopter falls more slowly. Model 2: a longer blade adds paper, so the helicopter is heavier and falls faster. Each model makes a prediction the other does not, and a fair test decides.
We are learning to
- write a hypothesis from a model, with its reason,
- state, before testing, the result that would show it wrong,
- use a test to choose between two models and refine the better one.
Success criteria
- I can write each model’s prediction for blades of 6, 8 and 10 cm.
- I can say which model the results support, and what would make me doubt it.
You need
- for each pair: three helicopters cut from the same paper with blades of 6, 8 and 10 cm and the same body, one paper clip each, a stopwatch or phone timer, a metre ruler,
- the two-models sheet (scaffold 1) for the record, and the cards from scaffold 3, one set per table. Drop from standing height on the floor: no chairs or desks.
Lesson flow (about 30 minutes)
| 5 min | Two models Show a helicopter and both models. Pairs write each model’s prediction for the three blade lengths, and the result that would show it wrong. Ask: “Both models sound sensible. What result would make you give up on Model 2?” |
| 12 min | Test Pairs drop each helicopter five times from the same raised-arm height, time each fall and find the mean. Show the board (see the box). Ask: “Which variables must stay the same so that only the blade length changes?” |
| 8 min | Decide and refine Pairs put their means on the board. Most classes find longer blades fall more slowly, though the gain shrinks. While the class compares, tables match the cards. Ask: “Model 1 wins, but is it the whole story? Where does Model 2’s idea still matter?” |
| 5 min | A sharper question Pairs write one new investigable question the result raises, such as what happens with blades of 14 cm. |
Running it shorter? Stop after the test, and pick up the decision and the cards in your next science lesson.
Watch for these ideas
- A “hypothesis” with no reason: it is only a guess until a model says why.
- Predictions so loose that any result fits them.
- Throwing a model away after one odd result instead of checking the method first.
Make it easier, make it bigger
- Easier: give pairs the two predictions written out, and ask only which result would count against each.
- Bigger: add paper clips to the 10 cm helicopter. When does Model 2’s extra mass start to win? Write a combined model.
Answers and look-fors
The next sheet has the worked two-models table, model answers for the hypothesis sheet, the card pairs, and a quick three-level guide.
Answers and look-fors
Two models, one test
From 10 to 40 °C the volume adds 6, 9, 14 mL (the steps grow) but multiplies by 1.67, 1.60, 1.58 (the factors stay close). Model A: a mean step of 9.7 mL predicts 47.7 mL at 50 °C. Model B: a mean factor of 1.62 predicts 61.6 mL. The measured value is 56 mL: Model B is closer (5.6 against 8.3 mL away), but neither is exact. A refined Model B lets the factor shrink a little as the temperature rises (the last step is only ×1.47), and more results between 40 and 50 °C would test that refinement. Collision theory explains the multiplying: each rise in temperature raises the share of collisions with enough energy to react, not just their number.
Hypothesis to prediction (rows 2 and 3)
| Topic | Variables and hypothesis | Prediction | Would show it wrong |
|---|---|---|---|
| Energy Flow and Climate Change | Change the gas in the bottle (air, or air with extra carbon dioxide); measure the rise in temperature (°C) after 10 minutes. If a bottle holds more carbon dioxide, it warms faster under the same lamp, because carbon dioxide absorbs infrared radiation and sends some of it back. | The carbon dioxide bottle ends a few degrees warmer than the air bottle; repeated, the gap is in the same direction every time. | The two bottles warm by the same amount, run after run. |
| Reaction Types and Rates | Change the size of the chips (large, small, powder), at the same total mass; measure the mass lost in the first minute (g). If the chips are smaller, they react faster, because more of the marble’s surface meets the acid, so more particles collide each second. | Powder loses mass fastest, then small chips, then large chips. | Large chips lose mass as fast as powder. |
Look for: the bottles start at the same temperature, sit the same distance from the lamp and are read the same way; the chips come from the same marble at the same total mass, in the same volume and concentration of acid.
What would prove it wrong? (card pairs)
| Cards | Hypothesis | Result that would count against it |
|---|---|---|
| G and A | If the force on a trolley doubles and its mass stays the same, its acceleration doubles. | Doubling the force leaves the acceleration almost the same. |
| D and J | If two pea plants that both carry one tall and one short allele (Tt) are crossed, about three-quarters of the offspring are tall. | Of 400 offspring, about 200 are tall. |
| E and L | If the acid is warmer, magnesium ribbon dissolves in it faster. | The ribbon takes the same time to dissolve at 20 °C and at 40 °C. |
| B and H | If beetles live on dark bark where birds hunt by sight, dark beetles survive better than pale ones. | Over many generations on dark bark, the share of dark beetles falls. |
| K and F | If an element is lower in Group 1, it reacts more vigorously with water. | Potassium reacts with water more gently than lithium does. |
| I and C | If a galaxy is further away, its light is shifted further towards the red. | The most distant galaxies show no more red shift than nearby ones. |
A quick three-level guide
| Move | Working towards | At standard | Beyond |
|---|---|---|---|
| Question | asks about a topic, not a relationship | names one variable to change and one to measure | chooses a question that can tell two models apart |
| Hypothesis | states an outcome with no reason | gives a direction and a reason from a model | predicts a size or shape and names the result that would show it wrong |
| Model | keeps a model whatever the data say | chooses the model the test supports | refines the better model where it misses, and says what to test next |
A student at standard writes a hypothesis with a reason and a prediction that could fail. The helicopters in the mini-lesson: longer blades usually fall more slowly, with smaller gains each time, so Model 1 wins while Model 2’s extra mass trims the gain.