Charles performed a C. laboratory experiment. This type of investigation involves manipulating variables (in this case, the type of salt) to observe the effect on the freezing point of water. He controlled conditions by using equal amounts of salt and identical beakers of water, which is characteristic of a laboratory experiment.
Charles knows that adding salt to water causes the freezing point of water to be lowered, but he wants to know if rock salt affects the freezing point more than table salt.
Charles performed an investigation in his classroom in which he measured the freezing point of 250 mL of water. He used this measurement as his control. Then, he dissolved equal amounts of rock salt and table salt in two identical 250 mL beakers of water. Finally, he measured the freezing points of each beaker of water, analyzed his results, and formed a conclusion.
What type of investigation did Charles perform?
A.
observational field study
B.
model-building
C.
laboratory experiment
D.
collection of specimens
1 answer