Which of the following is a solution?
muddy water
ranch salad dressing
brewed coffee
tomato juice

brewed coffee

Explanation:A solution is a homogeneous mixture of two or more substances. A solution must have a solute ( a substance that can be dissolved or a soluble substance) and a solvent (a substance, mostly liquid , that can dissolve another substance)

For a substance to be dissolved it depends on its degree of solubility.

For our example coffee beans (solutes) are dissolved in hot water which is a solvent and it becomes a homogeneous mixture which is a brewed coffee ; in which you can no longer separate a solute from a solvent. A solution is in one phase which can be either liquid or solid or gas , one can't see any particles in a solution with their makes eyes.

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.