Which reason best explains why metals are ductile instead of brittle? because they have rigid bonds because they have flexible bonds because they easily lose electrons because they easily gain electrons

because they have flexible bonds

Explanation:

edge 2021 :)

the answers are

c and c

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.