Amedeo Avogadro |

The Avogadro Constant *N _{A} *is well-known as a fairly large quantity
– in some parts of the world it is called Loschmidt’s number,

About 20 years ago a colleague in my then department rang me; he wanted
to get a pile of sand with For the sake of this order-of-magnitude calculation let’s assume that each grain
is a cube 0.1mm on a side, and that the grains pack perfectly with no spaces. Since it
makes the calculation marginally easier, let’s also deal with 10 |
Loschmidt |

It is better if you go through the calculation. So we shall do it step by step; click on the Next button to move further through the document.

- If each grain is 0.1mm on a side, using our assumptions how many grains are there in a cubic metre?