Answer :
Atomic mass Ca = 40.078 u.m.a
40.078 g --------------- 6.02x10²³ atoms
121 g ------------------- ??
121 x ( 6.02x10²³) / 40.078 =
7.28x10²⁵ / 40.078 = 1.81x10²⁴ atoms
40.078 g --------------- 6.02x10²³ atoms
121 g ------------------- ??
121 x ( 6.02x10²³) / 40.078 =
7.28x10²⁵ / 40.078 = 1.81x10²⁴ atoms