The diagram above suggests that a. the earth has not changed over geologic time. b. geologic time periods occur in repeating cycles. c. the earth has changed over geologic time. d. geologic eras occur in repeating cycles.

How does a scientist the government? a. the scientist tells people in society what to do. b. the scientist determines the policies that the government spends money on. c. the scientist provides unbiased information to the government. d. the scientist makes laws based on his or her research results.

Sally is making a model of a magnesium atom with an atomic mass number of 24 for her chemistry class. she has foam balls for the protons, neutrons, and electrons. she has added 6 neutrons to her model so far. how many more neutrons does she need to add to complete her neutral atom of magnesium?

Sulfuric acid is a polyprotic acid. write balanced chemical equations for the sequence of reactions that sulfuric acid can undergo when it's dissolved in water.