Boron is the fifth element in the periodic table so it always has 5 protons. However, different isotopes of bron have 3,5,6,7, or 8 neutrons in addition to the 5 protons to make up Boron-8, Boron-10, Boron 11, ect. As a research chemist for the Borax Soap Company you have been asked to use a mass spectrometer to determine the relative abundance of different isotopes of born in a sample. You decide to accelerate a beam of singly-ionized born ions. That is they have each lost one of their orbital electons and have one unit of positive net charge.

You decide to use an accelerating porential difference of -2.68 x 10^3 volts. The boron beam then enters a uniform magnetic field that has a direction perpendicular to the boron beam. You set up your electromagnet so its magnetic field has a magnitude of .182T. You observe two bright spots on your photographic plate and with the spot corresponding to a radius of 13.00cm having one fourth the intensity of the one corresponding to a radius of 13.61 cm. There are very faint spots at 11.53 cm, 14.17 cm, and 14.81 cm.

a) Calculate the masses of the particles at each of these spots to 4 significant figures.

b) Which isotope of boron has approcimatley 80% abundance? Which one has about 20% abundance? Which ones are present in only trance amounts? Show all calculations.