Question

how many atoms present in 8 gm of calcium

Answer 1

First convert the mass of Calcium given in 'g' to moles 'n' using:

n = m x M

n = 8 x 40.1

n = 320.8 moles

Now using n = N/NA

N = n x NA (Avogadro's number)

N = 1.93 x [10]x^{23}