A mole is just a number ...(Avagadro's number)...just a QUANTITY
it is 6.022 x 10^23 no dimensions, just a very large number.
Other definitions of a 'mole' (LOL)
1. a small burrowing insectivorous mammal with dark velvety fur, a long muzzle, and very small eyes.
2.a spy who achieves over a long period an important position within the security defenses of a country.