How do the number of valence electrons affect how likely a substance is to react with another substance?
The number of valence electrons is the number of electrons in the outer energy ring of an atom. The most electrons the first energy level of any atom can hold is two. The rest is 8. If the outer energy level is full, the atom will be less reactive because it cannot add any more electrons to it’s current outermost energy level. If it only needs one or two more electrons to fill it’s last energy level or if it only has one or two in it’s last energy level, it will be more reactive, because it only needs to gain a few or lose a few to be full.
