The number of Avogadro serves to know how many atoms there are in one mol. Now, a group of German chemicals has again measured this number and the result obtained does not correspond to the standard number. The question is not the accuracy, that is, they have not measured more decimal of the number, but have found the difference with the standard measurement in the million. It does not seem serious, but as used for a basic unit, what the Germans have discovered is of great importance.