michalchik

I want to develope a better intuitive understanding as to what we mean
by hardness. At the molecular level is hardness simply proportional to
the energy it takes to liberate a partical from the lattice? What do
we mean on a molecular level when we say something is 2, 5, 10 times
as hard? Does the definition of hardness have something to do with the
relative rate at which particals rub off two different substances?