I have grown up believing that Avogadro's number is a constant like the speed of light. However, there must have been attempts to get more accurate figures.

 

Just out of interest, I wonder what the number is now and how it is calculated?

I think it was established through experimental means rather than mathematically.

yep, its experimental. and seeing as we have very accurate measurements for the mass of atoms it is a relatively simple calculation.

 

what you do is, you take the value of 12grams (the mass of 1 mole of carbon-12 which is the accepted baseline) and divide it by the mass of 1 atom of carbon-12. this will give you the number of atoms in a mole.

 

there will be some error but it will be tiny and generally insignificant(on the order of maybe a few thousand atoms.)

I have grown up believing that Avogadro's number is a constant like the speed of light. However, there must have been attempts to get more accurate figures.

 

Just out of interest, I wonder what the number is now and how it is calculated?

 

6.022 141 79 (30) x 10^23 mol^-1

 

http://physics.nist.gov/cgi-bin/cuu/Value?na