Scenario: The effectiveness of various metals in preventing rusting of iron. Several weeks after Allen conducted a classroom experiment on the effectiveness of various metals in releasing hydrogen gas from hydrochloric acid, he read that the gas company was burying sheets of magnesium next to iron pipelines in order to prevent rusting. Allen wondered if other active metals would also be effective in preventing rust.

To investigate, he placed each of the following into a separate test tube containing water: one iron nail; one iron nail wrapped with an aluminum strip; one iron nail wrapped with a magnesium strip; and one iron nail wrapped in a lead strip. He used the same amounts of water from the same source, equal amounts of the metal wraps and the same type of iron nails. At the end of five days, he described the amounts of rusting either as small, moderate or large. He also recorded the color of the water.

Allen predicted that this the lead and aluminum would be less effective than the aluminum. Question 15 pts
What is the primary question under investigation in this scenario?
Group of answer choices

Will other metals rust as quickly as iron?

Will metals other iron prevent the rusting of iron?

Does magnesium dissolve as quickly as aluminum or lead?

Which type of iron nails are best for building with wood?
Question 25 pts
What is the analysts' hypothesis concerning the experiment?
Group of answer choices

The size of the test tubes will affect the rate of rusting more than the type of metal wrapped around the nail.

The rate of rusting will be unaffected by any of the other metals.

The magnesium will reduce the rate at which iron rusts more than the aluminum or lead.

The magnesium will reduce the rate at which iron rusts less than the aluminum or lead. Question 35 pts
What is the independent variable in this scenario?
Group of answer choices

the amount of time

the temperature

the amount of hydrochloric acid

the type of metal wrapped around the nail
Question 45 pts
What is the dependent variable in this scenario?
Group of answer choices

what type of metal is used

how much each nail rusts

how hard it is to wrap the test metal around the nail

the color of the waterQuestion 55 pts
What factors are kept constant in this scenario? Select all constants.
Group of answer choices

the amount of water

the source of the water

the type of test tube

the amount of metal wrapped around the nail