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Ch.7 - Periodic Properties of the Elements
Chapter 7, Problem 52

What is the relationship between the ionization energy of an anion with a 1- charge, such as F-, and the electron affinity of the neutral atom, F?

Verified step by step guidance
1
Step 1: Understand the concept of ionization energy, which is the energy required to remove an electron from an atom or ion in the gaseous state.
Step 2: Recognize that for an anion with a 1- charge, such as F-, ionization energy refers to the energy needed to remove an electron from the negatively charged ion to form the neutral atom.
Step 3: Understand the concept of electron affinity, which is the energy change that occurs when an electron is added to a neutral atom in the gaseous state to form an anion.
Step 4: Note that the ionization energy of F- is related to the electron affinity of F because both involve the addition or removal of an electron to/from the same element, but in opposite processes.
Step 5: Conclude that the ionization energy of F- is numerically equal to the negative of the electron affinity of F, as they represent reverse processes of electron addition and removal.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Ionization Energy

Ionization energy is the energy required to remove an electron from a neutral atom or ion in its gaseous state. For anions, such as F-, the ionization energy is relevant because it indicates how much energy is needed to convert the anion back to its neutral form by removing an additional electron. This concept is crucial for understanding the stability of anions and their reactivity.
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Electron Affinity

Electron affinity is the amount of energy released when an electron is added to a neutral atom in the gaseous state, forming an anion. For the element fluorine (F), the electron affinity is particularly high, indicating that it readily accepts an electron to form F-. This concept helps explain the formation of anions and their relationship to ionization energy.
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Relationship Between Ionization Energy and Electron Affinity

The relationship between ionization energy and electron affinity is significant in understanding the stability of anions. Generally, a high electron affinity corresponds to a lower ionization energy for the resulting anion, as the energy released during electron addition stabilizes the anion. This interplay is essential for predicting the behavior of anions in chemical reactions and their relative stabilities.
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