If the volume of a solid is 100 cm3 and its mass is 400 g, what is its density?

Based on the equation and the information in the table, what is the enthalpy of the reaction?

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?

Mary is conducting an experiment on how pollution affects plant growth. how can she ensure that her data are reliable?