present

  1. J

    How many fluorine atoms are present in 10 moles of SF6 (Sulfur Hexafluoride)

    I know I have to use avogadro number. The correct answer is 4 * 10 ^ 25 but how do you get that answer. Please help.
  2. F

    Percent Present Homework Questtion

    I've been stuck on this question and can't seem to figure out the right answer. Question: Heavy water has the formula D2O, and semi-deuterated water has the formula DHO, where D stands for deuterium. Using the data from the table, estimate the percentages of D2O and DHO present in natural...