Where might a spring form? between the saturated and unsaturated zones
at the bottom of a deep valley
on a mountaintop at the origin of a stream
on the surface of a fast-moving aquifer

what are the two models

explanation:

plasma - state of matter made up of electrically charged particles

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.