10. Given the reaction below, which is the reduced substance? Mg + Cl2 Mg2+ + 2Cl-

2Cl-

Explanation:

When a substance is reduced, it gains electrons. Because electrons are negatively charged, the substance that is reduced will have a negative charge. 2Cl- is the substance that was reduced because it became negative.

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.