How many atoms in 4.44(10^27) P4 O10 molecules?

Question

 chemistry

Answer 1

Each molecule of P₄O₁₀ has four atoms of phosphorous and 10 atoms of oxygen. That makes a total of 14 matoms per molecule. So multiply the number of molecules by 14 to get the total number of atoms. That would be 4.44 x 10^27 times 14, and that equals 6.216 x 10^28. But that answer has too many significant figures (four). The problem started with three significant figures and that means the answer can only have three significant figures. So the answer should be rounded to 6.22 x 10^28 to have the right number of significant figures.