Scientists have found fossils of tropical plants in Antarctica. How could tropical plants have grown in Antarctica?

What are the spectator ions in 2h+ + so42- + ca2+ + 2r → caso4 + 2h+ + 21?

Which of the following units is not an official si unit

Suppose that some of the compound spilled out of the crucible after it was heated. would that cause the percent by mass of water in the compound determined by the experiment to be too low, too high, or unchanged? briefly explain your answer.