Question

Of all boron atoms, 19.9%% are boron-10, which have a mass of 10.01294 amu. The other 80.1% of boron atoms are boron-11 and these have a mass of 11.00931. Calculate the average atomic mass of boron.

Answer 1

The average atomic mass of boron is 10.811 amu.

Step-by-step explanation:

The average atomic mass of boron can be calculated using the percentages and masses of its isotopes. In this case, we have two isotopes of boron: ¹⁰B, which makes up 19.9% of the atoms and has a mass of 10.01294 amu, and ¹¹B, which makes up 80.1% of the atoms and has a mass of 11.00931 amu.

To calculate the average atomic mass, we multiply the mass of each isotope by its percentage abundance and then add the results:

Average atomic mass = (mass of ¹⁰B)(abundance of ¹⁰B) + (mass of ¹¹B)(abundance of ¹¹B)

= (10.01294 amu)(0.199) + (11.00931 amu)(0.801)

= 2.001 amu + 8.810 amu

= 10.811 amu

Therefore, the average atomic mass of boron is 10.811 amu.

Answer 2

10.81 amu

Step-by-step explanation:

The average atomic mass of Boron can be calculated as follows :

`A=19.9\%\ \text{of}\ 10.01294 +80.1\%\ \text{of}\ 11.00931\\\\A=(19.9)/(100)* 10.01294 +(80.1)/(100)* 11.00931\\\\A=10.81\ \text{amu}`

So, the average atomic mass of boron is 10.81 amu.