How can you identify an element through its reactivity?

In order to identify an element based on reactivity, you need to refer to the periodic table. Each numbered column in a periodic table is a group. Each row is known as a period. When it comes to reactivity of elements, metals and non-metals are opposites on the periodic table. When looking at the metals in the periodic table, the reactivity of the element increases as you go down a group (column) and from right to left across a period (row). When looking at the non-metals in the periodic table, the reactivity decreases as you go down a group and from right to left across a period. If you are looking for the most reactive metal, you would find it in the bottom left corner of the periodic table. If you were looking for the most reactive non-metal, you would find it in the top right corner of the non-metals (excluding the noble gases). Noble gases are nonreactive because their outermost shell already has 8 electrons, which is considered stable.
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