Refers to the distance from one wave peak to the next wave peak. (Lesson 4.02)
A. frequency
B. wavelength
C. amplitude
D. medium

wavelenght

Explanation:

Wavelength can be defined as the distance between two successive crests or troughs of a wave. ... Wavelength is inversely proportional to frequency. This means the longer the wavelength, lower the frequency. In the same manner, shorter the wavelength, higher will be the frequency.

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.