Elements on the periodic table are organized by increasing atomic number. As atomic number increases, so does the number of electrons. Electrons, and specifically valence electrons, are important in determining how an atom interacts with other atoms. The elements in a vertical “group” have similar properties because they have the same number of valence electrons and similar electron configurations. This leads to smoothly varying trends in properties such as ionization energy, electronegativity, ionization energy, and atomic radius as one moves both down the groups and across the periods. Thus, the organization of the periodic table is useful for making predictions about an element based on its position in the table. The reactivity of the elements also follow well-defined trends both down the groups and across periods. In this activity, you will explore these trends in reactivity.
