The element boron has only two stable isotopes one stable isotope has a mass number of 10 and the other has a number of 11. what could be the atomic weight of the element?

Answer 1

From what I remember of chemistry, the amu of each element on the periodic chart is a weighted average of all the isotopes of that element. So, as you indicated - 80.2% of Boron exists as B-11 and 19.8% of boron exists as some other isotope. In that case you can get an estimate of the amu of the unknown through simple math: 0.802*(11.01 amu) + 0.198*(X amu) = 10.81 Solving for x, you get 10.00 amu

Answer 2

• well the The_average_mass_numbers_of_the_isotopes_of_an_elementThe_average_mass_numbers_of_the_isotopes_of_an_elementThe_average_mass_numbers_of_the_isotopes_of_an_elementThe_average_mass_numbers_of_the_isotopes_of_an_elementThe_average_mass_numbers_of_the_isotopes_of_an_elementThe_average_mass_numbers_of_the_isotopes_of_an_elementThe_average_mass_numbers_of_the_isotopes_of_an_elementThe_average_mass_numbers_of_the_isotopes_of_an_elementis the atomic mass. I thinks its 11 because if you look at the periodic table of elements it says 10.811 and that rounded to two significant digits is 11