the general rule of thumb is that the
a substance's atoms and the
the bonds, the harder the
substance will be

The general rule of thumb is that the SMALLER a substance's atoms and the STRONGER the bonds, the harder the substance. Two of the strongest forms of chemical bond are the ionic and the covalent bonds.

Explanation:

2b2t

explanation:

2b2t

that's what i got you can count the number of atoms