Why are some elements more reactive than others?
This is because of the number of electrons that they have on their outer shell and also due to the size and stability of the nucleus. The most stable of elements is iron although there are many less reactive elements than it. If an element is something like lithium in the first group of the periodic table then it is reactive as it only has one electron orbiting on the outer shell or at least furthest from the nucleus whilst those in the last group of the periodic table are the most stable as they do not have a partially filled shell.
