How does increased electronic shell distance from the nucleus affect reactivity?

The correctness of the answer is based on the fundamental principles of atomic structure and electron behavior within an atom. As the distance of the electronic shells from the nucleus increases, the outermost electrons are subjected to a weaker attractive force from the positively charged protons in the nucleus. This reduced attraction means that these outer electrons are held less tightly.

When it comes to reactivity, particularly among metals, increased distance from the nucleus allows these outer electrons to be lost more easily. This is especially important in chemical reactions where the loss of electrons is necessary, such as in the formation of positive ions (cations). For example, alkali metals in Group 1 of the periodic table, which have larger atomic radii and more electron shells, are very reactive due to their ease of losing the outermost electron.

In summary, the greater the distance of the electronic shells from the nucleus, the easier it is for an atom to lose its outer electrons and thus increase its reactivity.