Is it true that Avogadro did experiments to determine Avogadro's number?
No! Avogadro just guessed the average number of molecules,ions,atoms number in one mole of any compound,element,etc.
He didn't. Avogadro's number was simply named after Avogadro.
The Number Of Atoms (or molecules) In A Mole of a Substance. Equal to 6.02214179 × 1023 per mole.
Yes