Choose the element with the more negative (more exothermic) electron affinity from each pair. a. Na or Rb

Key Concepts

Electron Affinity

Electron affinity is the energy change that occurs when an electron is added to a neutral atom in the gas phase. A more negative electron affinity indicates that the process is more exothermic, meaning energy is released when the atom gains an electron. This property is crucial for understanding how easily an atom can accept an electron and form an anion.

Trends in the Periodic Table

Periodic trends refer to the predictable patterns observed in the properties of elements as you move across or down the periodic table. For electron affinity, it generally increases (becomes more negative) across a period from left to right and decreases down a group. Understanding these trends helps in predicting the electron affinity of elements based on their position in the periodic table.

Group 1 Elements

Group 1 elements, also known as alkali metals, include lithium, sodium, potassium, rubidium, cesium, and francium. These elements have low ionization energies and tend to lose one electron easily, making their electron affinities less negative compared to other groups. When comparing sodium (Na) and rubidium (Rb), it is essential to consider their positions in the group and how their atomic size affects their ability to attract additional electrons.