Iron, a metal, has which of the following features? electrons that transfer between atoms to make cations and anions
a sea of electrons
firmly bonded electrons
electrons shared between single pairs of atoms

football

explanation:

because it is

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.