How many molecules of PbSO4 are in 0.50 moles of PbSO4?

Which of the following would be an accurate picture of the earth during the summer time of the northern hemisphere?

Astudent is trying to create a table that compares hypotheses, theories, and laws. hypothesis theory law do scientific researchers formulate it? yes yes yes does it explain why things happen? yes yes no yes yes yes is it used to make predictions? no yes yes which of the following questions would most likely fill the blank in the table? is it an intelligent guess? is it newly formulated? is it based on observations? has it been proved?

One nanometer is equal to how many meters?