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: Air humidity, Air Temperature or Amount of metal corrosion

independent variable: Airborne salt concentrations, Volume of ocean water or ocean water temperature

one possible confounding variable: Air temperature, Airborne salt concentrations or color of nearby ocean waters

Electromagnets coils of wire paper clips picked up 10 3 15 6 20 9 25 12 ms. owens' class was studying magnets. ms. owens showed her students how to make an electromagnet using a nail, a d-cell battery, and plastic coated wire. the students wrapped the wire around the nail and then attached the ends to the battery. when they were finished, they tested their magnets by investigating how many paperclips their magnets could pick up. they also tested whether they could increase the strength of their electromagnets by using more coils of wire. they recorded the class average of their results in the data table seen here. ms. owens asked her students to graph their data in a line graph. how should the students label the x-axis on their line graph? a) size of battery b) number of paper clips c) number of coils of wire d) strength of electromagnet