List some variables that can change an experiment, and what is the importance of a control group?

temperature, light, amount of liquid or solid you should be measuring (human mistakes), inaccuracies in reading. Basically anything that may change the outcome, from if everything was done in the exact same conditions. Would help if we knew what the experiment was? A control group tells you what happens without any added liquids or substrates to the original liquid.

There are only 2 variables in an experiment.

Independent variable: is that one thing in the experiment that the scientist changes for themselves.

Dependent variable: the variable that changes because of the independent variable (what the scientist watches)

So in an experiment for finding out which metal is the best conductor of heat, the independent variable would be where the scientist changes the temperature. the dependent variable would be how hot the actual metal gets, if it does at all.

Controls are like a benchmark, that never changes in the entire experiment. It acts sometimes like a gauge.