Hey there!:
Molar mass Lead ( Pb ) = 207.2 g/mol
Therefore:
1 mole Pb --------------------- 6.02*10²³ atoms
? moles Pb -------------------- 2.31*10²¹ atoms
moles Pb = ( 2.31*10²¹ ) * 1 / ( 6.02*10²³ ) =
moles Pb = ( 2.31*10²¹ ) / ( 6.02*10²³ ) =
=> 0.00383 moles of Pb
Hope this helps !
