Question

ASAP

A carbon atom has a relative atomic mass of 13. 60% of the carbon atom has a mass number of 12.4, 30% of the carbon atoms have a mass number of 13.1, whilst the remaining 10% have a mass number which is not known.
Calculate the mass number of the carbon isotope which is 10% of the Carbon 13 atom.
Give your answer to 1 decimal place, if needed.

Answer 1

16.3.

Step-by-step explanation:

The average atomic mass of an element is calculated by weighing each isotope present and multiplying it by its percent abundance, and then adding all the values.

First, we'll find the weighted average of the isotopes present in 60% and 30% of the Carbon 13 atom:

0.6 * 12.4 + 0.3 * 13.1 = 7.44 + 3.93 = 11.37

Next, we'll subtract the weighted average of these two isotopes from the relative atomic mass of carbon:

13.0 - 11.37 = 1.63

This is the weighted average of the isotope present in the remaining 10% of the Carbon 13 atom. To find the mass number, we'll divide the weighted average by the atomic weight of the isotope:

1.63 / 0.1 = 16.3

So, the mass number of the carbon isotope present in 10% of the Carbon 13 atom is approximately 16.3.