Boron has two naturally-ocurring isotopes. boron-10 has an abundance of 19.8% and actual mass of 10.013 amu, and boron-11 has an abundance of 80.2% and actual mass of 11.009 amu. what is the average atomic mass for all isotopes of boron?

10.812  to the nearest thousandth,.

Explanation:

That would be 0.198 * 10.013 + 0.802 * 11.009

= 10.812.

i believe the answer is true.

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.