Year 8 science, stage by stage

What to do

1. Sit still for two minutes, then count your breaths for one minute. That is your resting rate.
2. Walk on the spot for one minute, then count your breaths for a minute straight after.
3. Rest until you are back to your resting rate, then repeat with one minute of star jumps.
4. Repeat the whole thing three times and work out a mean for each activity.

What to do

1. Chew a small piece of bread for five seconds and note the taste, then swallow.
2. Rinse with water. Chew a second piece for thirty seconds without swallowing, and note the taste.
3. Rinse again and repeat with a full minute of chewing.
4. Score the sweetness out of five each time and record it in a table.

What to do

1. Choose two similar leaves on the same plant. Photograph or sketch both.
2. Wrap one leaf completely in foil so no light reaches it. Leave the other uncovered.
3. Keep the plant in its normal spot and water it as usual for five days.
4. Unwrap the leaf and compare the two. Record the colour of each.

What to do

1. Put one teaspoon of yeast and one teaspoon of sugar in each glass.
2. Add 100 ml of cold water to the first, room-temperature water to the second and warm (not hot) water to the third.
3. Stir each once, then start the timer.
4. Measure the height of the froth in millimetres after 5, 10 and 15 minutes.

What to do

1. Lay your square on a shaded, damp patch of ground and gently look through the leaf litter.
2. Tally each type of animal you find. Do not pick anything up with bare hands.
3. Repeat on a dry, sunny patch of the same size for the same length of time.
4. Draw a bar chart comparing the two habitats, then sketch a food web from what you found.

What to do

1. Cut a strip of filter paper. Draw a pencil line 2 cm from the bottom and put an ink spot on it.
2. Hang the strip so the bottom edge sits in water but the ink spot stays above the water line.
3. Watch the water climb for about ten minutes, then take the strip out and let it dry.
4. Repeat with two other pens and compare how many colours each one separates into.

What to do

1. Tear up red cabbage, cover with hot water and leave to cool. Strain off the purple liquid.
2. Put an equal splash of indicator into each glass.
3. Add a teaspoon of one test liquid to each glass and record the colour.
4. Put your liquids in order from most acidic to most alkaline using the colours.

What to do

1. Fill each mug with the same volume of warm water and record the starting temperature.
2. Wrap one in foil, one in fabric and leave one bare as your control.
3. Record the temperature of each every two minutes for twenty minutes.
4. Plot all three sets of results as lines on one graph.

What to do

1. Hang a weight on 30 cm of string and time ten full swings. Repeat three times and take a mean.
2. Swap in a heavier weight, keeping the string exactly 30 cm. Time ten swings again.
3. Now go back to the first weight and try 15 cm, 30 cm and 45 cm of string.
4. Compare your two sets of results and decide which variable actually matters.

What to do

1. Stand a pencil in the glass of water and look from the side. Sketch exactly what you see.
2. Shine the torch into the water at a slant and note where the beam changes direction.
3. Rest the mirror in the tray at an angle and shine the torch onto it, catching the reflection on white paper.
4. Tilt the mirror slowly until a band of colours appears on the paper, then record the order.

What to do

1. Cut a 3 cm by 20 cm strip, split the top 8 cm into two wings and fold them opposite ways. Clip the bottom.
2. Drop it from a fixed height and time the fall. Repeat five times and take a mean.
3. Make copies with wings of 4 cm, 6 cm, 8 cm and 10 cm, keeping everything else identical.
4. Plot wing length against mean fall time and mark any anomalous result.

What to do

1. Drop the coin from exactly 1 m and time the fall. Do this ten times, recording every reading.
2. Calculate the mean of all ten, then the range from smallest to largest.
3. Circle any reading well outside the others and write down what might have caused it.
4. Recalculate the mean without the anomaly and compare the two means.

What to do

1. Fill one glass with 200 ml of cold water and the other with 200 ml of warm water. Let both stand for a minute so the water is still.
2. At the same moment, add exactly one drop of colouring to the centre of each glass. Do not stir.
3. Time how long each glass takes to become one even colour, checking every thirty seconds.
4. Repeat once more to check your result, then draw the two glasses at one minute, two minutes and five minutes.

What to do

1. Set up four identical pots with the same amount of cotton wool or compost and the same number of seeds. Label them A, B, C and D.
2. Mix the feed at four strengths: A gets plain water, B gets the dose on the bottle, C gets double, D gets four times.
3. Give each pot the same volume of its solution every day and keep them all on the same windowsill.
4. Measure the tallest shoot in each pot every two days for ten days, then plot height against day for all four pots on one graph.

What to do

1. Cut a 4 cm piece of straw, seal one end with blu-tack and weight the open end with the paperclip so it just barely floats upright in the jug. Adjust the blu-tack until it floats with only the top showing.
2. Drop your diver into the bottle, fill the bottle completely to the brim and screw the cap on tight.
3. Squeeze the sides of the bottle gently and watch the diver. Squeeze harder, then release. Record what happens at each pressure.
4. Push the bottle under water, squeeze and watch the water level inside the straw. Draw a labelled diagram of the air bubble at the surface and at the bottom.

What to do

1. Your partner holds the ruler at the 30 cm mark so it hangs between your open finger and thumb at zero. Without warning, they drop it, and you catch it.
2. Record the catch point in centimetres. Repeat ten times, swapping the hand you catch with after five.
3. Calculate the mean and the range for all ten catches, and mark any result that looks like an anomaly.
4. Write one sentence judging the method: how precise is a ruler marked in millimetres for measuring something this fast, and how could you improve reliability?