Question

If 1g Si contains 'n' atoms. Then calculate the number of atoms in 0.8g of calcium, with respect to 'n'. (Si=29, Ca=40).

Answer 1

No. of atoms in 1g Si = n
No. of atoms in 29g Si ( i.e 1mole) = 29n

No. of atoms in 1mole Si = No. of atoms in 1mole Ca = Avogadro's No.

So,
No. of atoms in 1mole Ca = 29n
i.e No. of atoms in 40g Ca = 29n
No. of atoms in 1g Ca $=\frac{29n}{40}=0.725n$
No. of atoms in 0.8g Ca = 0.725n × 0.8
= 0.57n