The number of Beryllium that are in 147g of mineral Beryl is calculated as below
find the moles of mineral Beryl = mass /molar mass
molar mass beryl mineral (Be3Al2Si6O18)= (9x3) +(27x2) +(28 x6) +(16 x18) = 537
= 147g/537 g/mol = 0.274 moles of Be3Al2Si6O18
find the moles Be in Beryl mineral
that is 3 x 0.274=0.822 moles since there is 3 molecules of Be in beryl mineral
mass of Be is therefore =moles of Be x molar mass of Be
0.822moles x 9 g/mol = 7.4 g of Be
