Marcos took a 100-cm cubed sample of suspension, shook it well, and poured equal amounts into four different test tubes. he placed one test tube in a rack, one in very hot water, one in warm water, and the fourth in ice water. He then observed the time it took for each suspension to settle. What was the variable in the experiment? What was the one constant.

The variable of the experiment was:

Temperature.

The constant of the experiment was:

The amount of the suspended material (100 cm)

Explanation:

First I want you to identify very well what a constant is and what a variable is, a constant is something that remains the same at different stages of the experiment or in different experiments (for example in this case the same amount of the same material in suspension was used), while a variable is something that is modified at each stage of the experiment (as you could notice, cold, warm and very hot water was used, as well as water at room temperature, so their temperatures were different).

Variable is temperature

Constant is the ammount