Respuesta :

Willchemistry
Molar mass of Calcium ( Ca ) = 40.078 g/mol

Number of moles in 9.8 grams :

1 mole Ca -----------> 40.078 g
mole Ca -------------> 9.8 g

moles Ca = 9.8 / 40.078

moles Ca = 0.2445 moles

number of molecules:

1 mole ----------------> 6.02x10²³ molecules
0.2445 moles --------> ?

= 0.2445 * 6.02x10²³

= 1.47x10²³ molecules

hope this helps!.