Question

the number of atoms in 120 gram of calcium and 12 gram of iron which one has more number of atom and how much is is the difference

Answer 1

by mole concept
atomic mass of ca = 40 g
40 g contains avagadroas no of atoms .i. e 6.023 10 ²³ atoms
now 120 gram contains. 6.023 X 10²³/40 X 120 =18.023 x10²³ or 1.823 X 10²² atoms
now atomic mass of iron is 56
56 gram contains 6.023 X 10²³ atoms
12 g contains 6.023 X 10²³/ 56 X 12= 1.29 X 10²³
so ca contains large no of atoms
now 18.023 - 1.29 X 10²³= 16.74 X 10²³
hope it works
mark brainy answer

Answer 2

Answer:

Molar mass of Calcium (Ca) = 40 g

We know that the number of atoms in 1 mole of any element is given by the "Avagadro number " which is 6.023 ×10^23 .

So, number of moles in 120 gm of Ca = 120/40

=3

So, number of atoms in 3 moles of Ca = 3 × 6.022×10^23 atoms.

=18.069 ×10^23

Molar mass of Iron (Fe) = 56

Number of moles in Fe = 120/56

=2.14

Number of atoms in 2.14 moles of Fe = 2.14 × 6.023 ×10^23

= 12.89 ×10^23

18.069 × 10^23 > 12.89 ×10^23

So, 120 g of Calcium has more atoms than 120 g of Iron.

Difference = 18.069 ×10^23 - 12.89×10^23

=5.179 ×10^23 atoms.