Design a fair test of a specific claim about a chemical reaction, correctly identifying the independent variable, dependent variable, and controlled variables.
Testing a scientific claim fairly requires a clear plan before touching any materials. Start with a specific, testable claim, then identify three things: the independent variable, the one factor you deliberately change between trials; the dependent variable, the one outcome you measure as a result; and the controlled variables, everything else that must be kept exactly the same so that any difference in your result can be blamed on the independent variable alone, not some other uncontrolled difference.
This week combines everything the last several weeks have set up: knowing the signs of a chemical reaction (week 30) and how enzymes and acid-base reactions can be sensitive to conditions like temperature (weeks 32-33) gives you real reactions worth testing claims about. A vague plan like "see what happens when I change stuff" is not a real experiment; a specific claim with clearly separated variables is.
Mastery looks like: They can correctly identify the independent variable, dependent variable, and at least two controlled variables for a given claim, and critique a flawed two-variable test.
Common stumbles: Confusing the independent and dependent variables; changing more than one variable between trials while believing the test is still fair.