What is the relationship between elements isotopes and elements atomic mass

Who is better, messi or cristiano, i need this for a chemistry class. asap

Asample of the male sex hormone testosterone, c19h28o2, contains 3.88×10^21 atoms of hydrogen.(a) how many atoms of carbon does it contain? (b) how many molecules of testosterone does it contain? (c) how many moles of testosterone does it contain? (d) what is the mass of this sample in grams?

Which of the following pairs of elements belong to the same groupa. h and he b. li and bec. c and pb d. ga and ge