How do scientists use sonar to study Earth’s oceans?

A to map the ocean floor

B to map ocean currents

C to measure underwater earthquakes

D to measure water density

the answer is c i believe

the answer is c

tell me if wrong

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.