Avogadro+A+LIGHT

Avogadro is a man who invented Avogadro's Number! go figure. His number is 6.022*10^23. Look familiar? it should, its the value of a mole. And the mole is one of the most usefull numbers ever discovered. its used to convert atomic mass into real mass, like grams and kilgrams.

(http://gemini.tntech.edu/~tfurtsch/scihist/perrin.gif)