The decay series for 238
92U is represented in Figure 19.1. Write the balanced
nuclear equation for each of the following radioactive decays.
a. Alpha-particle production by 226
88 Ra
b. Beta-particle production by 214
82 Pb

i think its 100

i hope this !

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.