# Do elements have similar chemical and physical properties when they are located in the same group or period?

Elements display the same chemistry when they lie in the same $\text{Group}$, the same column of the $\text{Periodic Table}$.
The $\text{Periodic Table}$ reflects electronic structure; i.e. specifically the number and symmetry of the valence electrons. Given the same number of valence electrons, elements of the same Group should exhibit similar chemistry, as indeed they do.
The alkali metals, and alkaline earth metals, are from $\text{Group 1}$ and $\text{Group 2}$ respectively. Each group possesses a characterisitic chemistry. At the other end of the table, $\text{Group 16}$, the chalcogens, $\text{Group 17}$, the halogens, also have characteristic electronic structure, and to a first approximation this dictates similar chemistry for each individual $\text{Group}$.