Question

18 ccc patterns electron affinity and ionization energy appear to be opposing concepts. explain, using main group elements only, why they both share similar periodic trends in a period and column.

Explanation:

Electron affinity is the energy change when an electron is added, ionization energy is the energy to remove an electron. In a period, as nuclear charge increases, both attracting electrons (higher electron - affinity) and holding them tightly (higher ionization energy) increase. In a group, as atomic size increases, outer - electrons are farther from the nucleus, reducing both the ability to attract new electrons (lower electron - affinity) and the energy to remove an electron (lower ionization energy).

Answer:

Both electron affinity and ionization energy trends are governed by nuclear charge and atomic size. In a period, increasing nuclear charge leads to higher values for both. In a group, increasing atomic size leads to lower values for both.