ok i am an ib student doing chem lets see if this answers your questen. if you want the identity of an atom inside a unknow compound you either need to have some fancy equiment or to know every thing else inside the compound and know the moles present ans the mass of the whole molecule. if you want to know the number of atoms then there are a few ways to go depending on what you have been given. if you know the molecular formula and you know how many moles there is then you simply need to times by avogadro's number. avogadro's number is 6.02214179(30)×1023 . but you can just do it to 6.02. this will give you the number of molecules. then you just times by the number of atoms in the molecule.
here is an example
6 moles of glucose
6 C6 H12 O6
6×6.02×1023 =3.612 ×1024
now to find carbon simply times by 6 again because there are 6 carbon in each molecule of glucose.
The subscript, the little number below and after the element, tells how many atoms are in a single molecule.
The subscript in a formula typically indicates the number of atoms of an element present in a molecule. It is used to specify the ratio of atoms in a compound or the number of atoms in a polyatomic ion.
coefficients
The subscript number after a chemical symbol indicates how many atoms of that element are present in a single molecule of the compound.
The subscript in a chemical formula refers to the number of atoms of that element present in the molecule. It is a small number written at the lower right of the element symbol. For example, in the formula H2O, the subscript 2 indicates that there are two hydrogen atoms in each water molecule.
The subscript, the little number below and after the element, tells how many atoms are in a single molecule.
That would be called chemical analysis. If you just want to know what the compound is, that is a qualitative analysis, and if you want to know exactly how much of it you have, that is a quantitative analysis.
The subscript in a formula typically indicates the number of atoms of an element present in a molecule. It is used to specify the ratio of atoms in a compound or the number of atoms in a polyatomic ion.
coefficients
The subscript number after a chemical symbol indicates how many atoms of that element are present in a single molecule of the compound.
coefficients
The smallest representative unit of a substance is called a molecule. The number and type of atoms present in a molecule are determined by the chemical formula of the substance. The chemical formula provides information on the number and type of each element present in the molecule.
The subscript in a chemical formula refers to the number of atoms of that element present in the molecule. It is a small number written at the lower right of the element symbol. For example, in the formula H2O, the subscript 2 indicates that there are two hydrogen atoms in each water molecule.
The subscript in a chemical formula indicates the number of identical molecules present. For example, H2O indicates two molecules of water present.
The 3 means there are 3 molecules of H2O (water), and the 2 is a subscript and means there are 2 atoms of hydrogen (H) in one molecule.
In chemical compounds, subscripts indicate how many of that element are present in the compound, compared to the rest of the compound.In MgCl2, the subscript indicates that there are two chlorine atoms for every atom of magnesium.
The total number of atoms present in the molecule CH3NH2 is 7. This includes one carbon atom, four hydrogen atoms, and two nitrogen atoms.