Draw a Bohr model showing the number of
protons and neutrons and the electron
arrangement (including pairs and single
electrons) for these atoms.
(a) hydrogen-1
(b) hydrogen-2
(c) beryllium-9
(d) magnesium-26
(e) sulfur-36

yes it is balanced

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.