why might it be useful for scientists to have multiple models for describing earth's interior structure? describe how one model might be more useful than the other depending on context

Can someone me with 3 and 4 plz. this is for masteries test.

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?

The appropriate concentration for an iodine sanitizer is