Mixture is composed of molecules of different types. A compound can only be separated through chemical means. While a compound is a pure substance that contains 2 or more elements chemically combined together while a mixture are formed when two substances are added together without chemical bonds being formed.
Given the mass of
=25.6 g
The molar mass of
=390.35g/mol
Converting mass of
to moles:

Converting mol
to mol S:

Converting mol S to atoms of S using Avogadro's number:
1 mol = 

A civilização egípcia se desenvolveu ao longo do rio Nilo em grande parte porque as enchentes anuais do rio garantiam um solo rico e confiável para o cultivo.