A student recently asked me why successive electron affinities can have negative values. Here’s a quick explanation: First, let’s clarify what we mean by successive electron affinity. It refers to the energy change when adding a second, third, or subsequent electron to an already negatively charged ion, after one electron has been added to the … Read more
Generally, ionization energy increases across a period from left to right. If you need a quick refresher, here’s why: As you move across a period, the nuclear charge increases, but the number of energy levels stays the same. At the same time, the atomic size decreases, pulling the electrons closer to the nucleus. Because the … Read more
Answer No. Atomic radii DECREASE as we move from left to right across a period in the periodic table. The table below, for example, shows the atomic radii of Period 3 elements—you can observe a steady decrease from sodium (Na) to argon (Ar) through magnesium (Mg), aluminum (Al), silicon (Si), phosphorus (P), sulfur (S), and … Read more
In the previous section, we saw that since the exact size of an atom is difficult to determine, chemists use different types of atomic radii—such as covalent, van der Waals, ionic, and metallic radii—each defined according to the type of bonding involved. There is also the Bragg–Slater radius, which provides another way to estimate atomic … Read more
The term atomic radius generally refers to the distance from the center of an atom’s nucleus to the outermost shell of its electrons. However, determining the exact size of an atom is challenging because atoms do not have sharply defined boundaries. Moreover, it’s impossible to isolate a single atom and measure its radius directly. Therefore, … Read more