Group 7 elements, commonly referred to as halogens, exhibit similar chemical properties due to their electronic configuration, specifically because they each possess seven electrons in their outermost shell.

The elements classified as halogens in the periodic table include fluorine ($\text{F}$), chlorine ($\text{Cl}$), bromine ($\text{Br}$), iodine ($\text{I}$), and astatine ($\text{At}$). These elements share a fundamental characteristic: they all have seven electrons in their outer energy level, which plays a crucial role in determining their reactivity and ability to bond with other atoms.

The halogens are particularly reactive because having seven electrons places them just one electron short of a complete outer shell. A full outer shell corresponds to a highly stable configuration for an atom. Consequently, halogens tend to readily gain an additional electron to achieve this stable state. This reactivity is why halogens are predominantly found in nature as part of compounds rather than in their elemental forms.

When halogens react with metals, they form salts, and when dissolved in water, they produce acidic solutions. Furthermore, there are observable trends in their physical properties as one moves down the group. For instance, as you progress down the group, the halogens become darker in color, exhibit higher melting and boiling points, and show decreased reactivity. These trends can be attributed to the increasing number of electron shells and the greater atomic radius, which makes it more challenging for the atom to attract an additional electron.

In summary, the analogous chemical properties of the Group 7 elements stem from their similar electronic configurations. Their reactivity and the types of compounds they form are fundamentally influenced by their inclination to gain an electron in order to achieve a full outer shell.