5o2 is a Compound not an element
Simple. The atomic number is the number of protons (12) and the mass number is the number of neutrons and protons combined. So you'd subtract 12 from 25 (25-12=) and that'd get you 13 as your answer. If you need to find the number of electrons, it'll be the same as the number of protons unless it has a certain charge and if it does, if it's positive it has more protons (+) than electrons (-), if it is negative it has more electrons (- negatively charged) than protons (+ positively charged)
10000. millimeters. is. correct
Answer:
which formula can be used to calculate the molar mass of hydrogen peroxide (H2O2)?
» <u>d.2 x molar mass of H + 2 x molar mass of O</u>
Explanation:
Since we've two hydrogen atoms and two oxygen atoms, we multiply each mass by 2

Which of the following statements best defines the actual yield of a reaction?
»<u> </u><u>d.The ratio of measured yield over stoichiometric yield</u>