Science
lab files
Step-by-step lab files, printable data sheets with answer keys, and browser tools for middle and high school science.
// Core skills
Every lab on this site trains the same four skills, in the same order you use them at the bench.
Hypothesize
Write an if, then, because prediction you can test.
Control
Change one variable. Keep every other condition the same.
Measure
Read the meniscus, the balance and the ruler to the right precision.
Explain
Turn the data table and graph into a conclusion.
// Independent vs dependent
Independent
What you change- Chosen before the test
- Plotted on the x-axis
- One per experiment
Dependent
What you measure- Recorded in every trial
- Plotted on the y-axis
- Always has a unit
// Start here
New to lab write-ups? Start with the scientific method, then learn the variables every fair test needs.
// Lab files 6 of 28
Osmosis egg lab
Soak a shell-less egg in water and corn syrup, then track how its mass changes to see osmosis in action.
Gummy bear osmosis
Soak gummy bears in water, salt water and vinegar overnight, then measure which one swelled the most.
Elephant toothpaste
Yeast breaks down 3% hydrogen peroxide into a fast column of oxygen foam — test how the amount of yeast changes it.
Pendulum period
Change the string length, time ten swings, and graph T² against L to find the pattern behind a pendulum's rhythm.
Drops on a penny
Count how many drops of water a penny holds before the dome collapses, then test what soap does to that number.
Strawberry DNA
Mash strawberries with a soap-and-salt buffer, filter, then float DNA out of solution with cold rubbing alcohol.
// Tools
Practice the skill on screen before you need it in the lab.