A carbon atom has a relative atomic mass of 13.5. 60% of the carbon atom has a mass number of 12, 30% of the carbon atoms have a mass number of 13.6, 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 13.5 atom.
Give your answer to 1 decimal place, if needed.
