2.What does it mean when a wave's amplitude increases? A. Its frequency also increases. incorrect answer
B. It's moving through a denser medium. incorrect answer
C. Its wavelength gets longer. incorrect answer
D. It's carrying more energy.

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.