Eleven guided investigations become working models.

Predict before results appear, change one variable, receive safety-aware feedback, and collect evidence. These original models support inquiry; they do not replace supervised practical science.

20/20topics now interactive11 new • 9 established

Chemistry • P6–S2

Water filtration

How does filter depth affect clarity?

Guidance language

Predict

What do you expect?02

Change one variable

Filter depth4 cm

ShallowDeep

Model outputRun the model after predicting

Record evidence

Compare the output with your prediction, repeat at two more settings, then explain the pattern and one limitation of the model.

✓ Prediction before result✓ One variable changed○ Three trials required○ Explanation pending