Question

Calculate the number of atoms in 100amu of He

Answer 1

the number of atoms in 100 amu of helium is 25

Answer 2

The number of atoms present in 100 amu of helium is 25 atoms.

To find:

Number of atoms = ?

Solution:

The number of atoms present in 100 amu of helium is to be calculated by using simple unitary method knowing that the a.m.u. is the atomic mass unit which itself represent the mass.

So thereby, we need to know the "mass of one atom" and that can be divided to know the "number of atoms".

Therefore,

The "mass of one atom" of helium is known to be 4 a.m.u.

Thereby,

$\text{Number of atoms} = \frac{\text{Total mass of atoms}}{\text{Mass of one atom}}$

$\text{Number of atoms in 100 amu} = \frac{100}{4}=25$