What kind of investigative never includes a hypothesis

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation:

What is the percent composition of ca(oh)2? 37.7% ca, 53.0% o, and 10.3% h 45.5% ca, 38.2% o, and 16.3% h 54.0% ca, 43.0% o, and 2.7% h 64.7% ca, 27.0% o, and 8.3% h

Scientists have developed an explanation of a phenomenon from several verified hypotheses. the explanation has been confirmed through numerous experimental tests.which option best describes this explanation? a. scientific lawb. research questionc. hypothesisd. scientific theory