The Valence electrons determine an atom's ?

The valence electrons determine an atom's reactivity.

Explanation:

The valence electrons is the electrons on the most outer layer of an atom. The higher the number of valence electrons, the bigger the reactivity of the atom. This means that when that atom is put with another substance and it reacts, it would react in a much more violent way than another atom with lower valence electrons.

r = ρ x length / area  

ρ = r x area / length  

ρ is in ohm-meters  

in basic units, it is m³kg/s³a²  

i think this is it.