1) which of the following is the least reactive? alkali metals alkaline-earth metals noble gases 2)which describes how elements are arranged in the periodic table? z by chemical symbol by increasing atomic number by alphabetical order of name 3)which of the following groups have a complete set of electrons in their outer shell? alkaline-earth metals halogens noble gases 4)from the results of his experiments, moseley was able to determine the number of in an atom. protons neutrons electrons 5)mendeleev arranged the elements in order of increasing atomic mass alphabetically randomly