Anyone know the answer ?

The correct answer is: Avogadro

The Avogadro constant (NA or L) is the proportionality factor that relates the number of constituent particles (usually molecules, atoms or ions) in a sample with the amount of substance in that sample. Its SI unit is the reciprocal mole, and it is defined as NA = 6.02214076×1023 mol−1.

The answer is Avogadro.

Explanation:

Here are the examples :

The mass of a single carbon-12 atom has been found to be 1.992×10^-23 g using a mass spectrometer. The number of atoms in exactly one mole of 12C is 6.02×10^23. This can be shown by the following calculation.

Na = Mass per mole of 12C ÷ Mass of one atom of 12C

= 12g/mol ÷ 1.992×10^-23

= 6.02 × 10^23 mol^-1

Thus one mole of any substance contains 6.02×10^23 particles. This number is called the Avogadro constant.

So that 12g of the element carbon , 1 g of the element hydrogen and 32g of the element sulphur contains 6.02×10^23 atoms even though the element carbon exist as atoms, and Hydrogen and sulphur exist as molecules.

I hope it can help you