Question

The J = 0 → J = 1 rotational absorption line occurs at wavelength 0.0026 in C¹²O¹⁶ and at 0.00272 m in C^xO¹⁶. Find the mass number of the unknown Carbon isotope.

Answer 1

Using (2) in (1) and solving for x, we get x = 13.004. Hence the mass number is 13.