Write the balanced equation for the reaction of lead (II) nitrate with sodium iodide to form sodium nitrate and lead (II) iodide

Joan writes four numbers on the board in standard form, and then she writes their scientific notation

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.

Which substance can be broken down by chemical means