Group 2 elements in the periodic table, also known as alkaline earth metals, include beryllium Be , magnesium Mg , calcium Ca , strontium Sr , barium Ba , and radium Ra . These elements have their outermost electron in the s-orbital of their respective energy levels. The electronic configuration of Group 2 elements can be represented as ns^2, where n is the principal quantum number.The reactivity trend of Group 2 elements increases as you move down the group. This is because the atomic size increases down the group due to the addition of electron shells. As a result, the outermost electrons are further away from the nucleus and are less tightly held by the positive charge of the protons in the nucleus. This makes it easier for these elements to lose their outermost electrons and form +2 ions, which is the basis of their reactivity.In summary, the reactivity of Group 2 elements increases down the group due to the increasing atomic size, which results in weaker attraction between the outermost electrons and the nucleus, making it easier for these elements to lose electrons and participate in chemical reactions.