What number of magnesium ATOMS are contained in a #12*g# mass of the metal? Chemistry The Mole Concept The Mole 1 Answer anor277 Mar 16, 2017 #"Number of atoms......= "3.011xx10^23# Explanation: #"Number of atoms of Mg"# #-=# #"Mass of metal"/"Molar mass of metal"xxN_A#, where #N_A-="Avogadro's number"=6.022xx10^23*mol^-1# And so to business, #"Number of atoms of Mg"# #-=# #(12*g)/(24.31*g*mol^-1)xxN_A#, #=1/2*cancel(mol)xx6.022xx10^23*cancel(mol^-1)# #=3.011xx10^23#, a #"noomber"# as required......... Answer link Related questions How do you calculate the number of moles from volume? How do you convert grams to mole? Question #258e5 Question #8d48c Why is the mole an important unit to chemists? What's the mole number? How does the mole relate to carbon 12? How does the mole relate to molecules and ions? How do you calculate the moles of a substance? How can I calculate the moles of a solute? See all questions in The Mole Impact of this question 1206 views around the world You can reuse this answer Creative Commons License