What determines of something is reactive or nonreactive?

Answer 1

Reactions occur with Valence electrons. These are the outermost layer of electrons. In chemistry, there is a rule called the Octet rule, which says that atoms what to be as stable as possible and will do whatever they can do achieve that goal. For example, Sodium wants to lose 1 electron so that it can have a full outer shell of electrons (8). Thus, Sodium will very easily lose an electron to another element and is very reactive. Also, as you move down the Periodic Table and to the left, elements tend to be more reactive.

Answer 2

The reactivity of a substance is determined by its electron configuration and availability of electrons. Substances with unpaired electrons or high energy levels are often more reactive, while those with full electron shells tend to be nonreactive. Additionally, the nature of the atoms involved and the type of chemical bonds present can also influence reactivity.