Someone help me please

What is the mass of phosphorous in a 51-kg person

What are the coefficients to balance the following equation? ba+br=babr2

Select the correct answer. why are scientific models important in the study of science? a. they always involve critical mathematical calculations. b. they scientists understand complex ideas and objects that aren’t easy to handle. c. they enable scientists to popularize their work in society. d. they are required when conducting any peer review process. e. they are necessary for turning a hypothesis into a law.