A generic Lewis structure is given where Y represents the central atom and the outer atoms are represented by X. The outer atoms are not necessarily all the same element. Lewis structure showing Y X 4. Y is central with a lone pair of electrons and four X attached by single bonds. Each X has three lone pairs of electrons. Which compound is represented by the generic Lewis structure

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.