Where is the most of the mass of an atom located? a) in the nucleus b) in the orbits c) in the electrons d) its split between the nucleus and the orbits

Ineed ! i have no clue how to do this problem.

Which of the following is not one of the steps in the scientific method a. hypothesize b. summarize c. analyze d. familiarize

Suppose you mix one mole of sulfuric acid (h2so4) with 1 mole of sodium hydroxide(naoh). why does the ph of the solution remain below 7? ( explain so i can get better understanding! )