Answer to Question #70935 in General Chemistry for David Ballad

Question

How does each group of elements illustrate the Periodic Law?

Answer 1

The periodic law states that the properties (physical and chemical) of the elements depend on their atomic numbers. From top to bottom in a group the atomic radius increases (because of the increasing number of the energy levels), the ionization energy decreases (since the valence electrons are farther away from the nucleus and the attractive forces are weaker), the electronegativity decreases (due to the longer distance between the nucleus and the valence electron shell). Consequently, while the values of the atomic radius increase and the values of the ionization energy and the electronegativity decrease, the metallic character from top to bottom in a group will strengthen. Conversely, nonmetallic character increases from bottom to top in a group.