What is mole concept and muscular mass

the mole concept :

a mole (mol) is defined as the amount of substance that contains as many atoms, molecules, icons, electrons or any other elementary entities as there are carbon atoms in exactly 12 gm of. the number of atoms in 12gm of is called Avogadro's number.

I'm not sure about muscular mass sorr

they are all solids.

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.