The below reaction is a good example of a(n) ___ reaction. 3Ca(OH)2 + 2H3PO4 --> Ca3(PO4)2 + 6H2O (A) double replacement (B) single replacement (C) synthesis (D) decomposition

since electrons are negative the answer is neagtaive

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.