Question

1. The mass of a single atom of an element X is 2.65 x 10^-23 g. What is its atomic mass? What could this element be?

Answer 1

Mass of one atom=2.65×10^-23g

As we know that 1 mole of any atom=6.022×10²³ atoms

or we can say that 6.022×10²³ atoms have mass= 1 mole=atomic mass of that element

Now mass of one atom=2.65×10^-23g

then mass of 6.022×10²³ atoms will have= (2.65×10^-23)×(6.022×10²³) u

= 15.9×10^-23×10²³

= 15.9×10^(-23+23)

= 15.9×10⁰=15.9×1=15.9u

Hence atomic mass of the element is=15.9u Or ≈ 16.0 u

which is the atomic mass of O(oxygen)

so this element is oxygen.