Democritus thought that matter was made of tiny particles
a. of earth, air, fire, and water.
b. that could not be divided.
c. that could be divided.
d. that were all round and smooth.

Madison lives near the ocean. she’s formed a hypothesis that increased concentrations of salt in the air speeds the corrosion of certain metals. if madison plans to test this hypothesis, she will have to deal with the following variables in her experiment: dependent variable: independent variable: one possible confounding variable: