How do you work out the percent abundance of two boron isotopes?

To determine the percent abundance of two boron isotopes, you would typically need experimental data from a mass spectrometry analysis. The percent abundance can be calculated by comparing the relative intensities of the peaks corresponding to the two isotopes in the mass spectrum. By dividing the intensity of each isotope by the sum of both isotopes' intensities and multiplying by 100, you can find the percent abundance of each isotope.