What happens to the reactivity of group 1 elements as you move down the group?

As you move down Group 1 of the periodic table, which includes alkali metals such as lithium, sodium, and potassium, the reactivity of these elements increases. This trend can be attributed to several key factors related to atomic structure.

First, as you go down the group, each successive element has an additional electron shell. For instance, lithium has two shells, while sodium has three, and potassium has four. This increase in the number of shells creates greater distances between the outermost electron and the nucleus, leading to a decrease in the effective nuclear charge experienced by that electron.

As a result, the outermost electron becomes more loosely held and is more easily lost in chemical reactions. This increased ease of losing the outer electron is what enhances the reactivity of the alkali metals as you descend down the group.

Additionally, the shield effect—where inner shell electrons repulse outer electrons and reduce the effective pull of the nucleus—also contributes to this increased reactivity. With more inner shells, the shielding effect is more pronounced down the group, effectively making it easier for the outer electron to be removed.

In summary, the increasing atomic radius, decreasing effective nuclear charge, and the enhanced shielding effect all combine to make group 1 elements