What happens in a stationary front?
A. A warm air mass collides with a stationary cold air mass, and
slides under it B . A warm air mass catches up to a moving cold air mass, sliding
over it
C. A cold air mass and a warm air mass meet, with neither moving.
OD. A cold air mass catches up to a moving warm air mass.

c a cold air mass and a warm air mass meet with neither moving

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.