Question

What is a mole and why does a mole of carbon and a mole of magnesium for example weigh different if they have the same number of atoms(

Answer 1

Mole is a quantity corresponding to
`6.022\cdot 10^(23)` of units;

Difference in molar mass produces different masses for the same number of moles of two substances

Step-by-step explanation:

We can define a mole very easily. Mole may be considered in any system, not only in chemistry. However, mole is mostly significant in chemistry.

Mole is simply a unit of measurement which is equal to the Avogadro's number of objects. That is, if we have 1 mole of some specific object, it means we have a total of Avogadro's number (
stones.

Since this is a very huge number, we mainly use moles in chemistry to represent the number of molecules, atoms or ions.

You defined it perfectly: if we have 1 mol of C and 1 mol of Mg, they both contain the same number of atoms, that is, a total of
`6.022\cdot 10^(23)` atoms.

The problem is, however, that each individual atom of magnesium weighs more than the carbon atom. If you look at the periodic table, the molar mass of magnesium is 24.305 g/mol, while the molar mass of carbon is 12.011 g/mol. Magnesium atom is more than twice as heavy as carbon.

According to the molar mass, 1 mol of magnesium contains 24.305 grams and 1 mol of carbon contains 12.011 grams. This is essentially due to a different nature of atoms, they have different masses.

Take, for comparison, one stone and one feather. Although we have one of each, stones weigh more than feathers.