Cu + 2 H2SO4 → CuSO4 + 2 H2O + SO2 Look at the above reaction, what is the name of the acid on the REACTANT side of the equation?

c (diamond),

sio2 (quartz)

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.