Knowing she could reduce the candlestick (Au203) from earlier down and obtain pure gold (Au), Anna Littical set upon the chemical reaction. After massing the candlestick
back in the lab, she discovered the candlestick (Au203) had a mass of 475 grams, how
many grams of silver should the chemistry student be able to recover? (Hint: find
percent composition of Au in Au203 first.)
a) 0.268 grams Au
c) 296 g Au
b) 408 grams Agu
d) 393 grams Au

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.