Respuesta :

Willchemistry
Atomic mass Calcium ( Ca) = 40.078 u.m.a

40.078 g --------------- 6.02x10²³ atoms
187 g ------------------- ??

187 x ( 6.02x10²³) / 40.078 =

1.125x10²⁶ / 40.078 = 2.808x10²⁴ atoms

hope this helps!