Which of the following elements is a rare earth metal?

a. sc
b. ar
c. fr
d. pm

Why did southern business leaders want to increase the number of slaves

How many moles of potassium hydroxide are needed to completely react with 2.94 moles of aluminum sulfate according to the following equation:

Malik formed a hypothesis that an increase in atmospheric oxygen levels by 10% would cause red-legged grasshoppers to grow larger than normal. suppose that malik performs an experiment to test his hypothesis. which of these actions would represent a scientific mistake in his experiment? a. he experiments on live grasshoppers instead of preserved ones. b. he focuses on red-legged grasshoppers instead of all kinds of grasshoppers. c. he varies the nitrogen and carbon dioxide levels in the air from one trial to the next. d. he conducts the experiment in a controlled lab setting with a lab partner. e. he measures the mass and length of his specimens at the start of each trial.