Tasks
Practical tasks
A short experiment shows you a phenomenon; a week-long observation teaches patience and accuracy. This section has two tasks that run over several days, plus a list of signs that the work went well. Each task needs an adult helper and a notebook you don't mind filling up.
A week of modest but regular notes gives you more than one spectacular experiment that leaves nothing in your notebook but a date.
How this section works: the tasks are set out step by step and need nothing but ordinary household items. The number of days is approximate — if the shoots appear later, simply extend the observation and note it in your diary.
A one-week task: the shoot turns towards the light
Sprout the seeds
Spread a few bean or pea seeds on a damp paper towel in a clear container. Check every day that the towel hasn't dried out and add a little water carefully.
Plant the shoots
When shoots appear, plant them in two small pots of soil. One pot will be the control: it stays on an open windowsill.
You need a control so that you have something to compare with.
Build the box
The adult cuts a palm-sized window in the side of a cardboard box. The second pot goes inside, and the box is turned so the window faces the light.
Write down your hypothesis
Before you start observing, write what you think will happen to the shoot in the box and how it will differ from the control.
Observe every day
At the same time each day, open the box, draw both shoots and note which way the stem is leaning. If there's a phone handy, the adult can photograph the plants from the same spot.
Draw a conclusion
After a week, compare your drawings. Plants grow towards light, and scientists call this phototropism. Did the result match your guess?
A three-evening task: how water freezes
Prepare the cups
Take two identical plastic cups. Fill the first one halfway and the second almost to the top, and mark the water level with a felt-tip pen.
Make a guess
Write down what will happen to the water level after freezing: will it stay the same, drop or rise?
Put them in the freezer
The adult places the cups on a level shelf in the freezer. Don't use glass or closed bottles: water expands as it freezes, and glassware can crack.
Check in the morning
Compare the height of the ice with your marks. Measure the difference with a ruler and write down the numbers for both cups.
Watch the ice melt
Leave the cups on a plate at room temperature and every half hour note how much ice is left. In the evening, compare which cup melted faster.
How to tell the task went well
- The hypothesis was written down before the experiment, not made up afterwards.
- The diary has an entry for every day, even if nothing changed.
- The conditions are noted: where the plant or cup stood, how much water there was, what time of day it was.
- The conclusion is based on what you saw, not on what a book says.
- You can explain to someone else how to repeat your experiment.
Related sections
- Lessons
Short observation lessons by topic: what exactly we see in each experiment and why it happens.
- Methods
The scientific method in simple words, an observation diary and presenting your result in class.
- Questions
Answers about safety, experiments that didn't work and how to present your work for a project.
Sources
- Guides for young researchers (in general terms)
- Safety rules for experiments (in general terms)
The experiments are described in general terms, based on school science textbooks, guides for young researchers and safety rules. Results at home may differ from what you expect, so repeat each experiment together with an adult and write down honestly what you actually saw.