Electron Gain Calculator

What is Electron Gain?

Electron gain, also known as electron affinity, is the energy change that occurs when an electron is added to a neutral atom in its gaseous state. It's an important concept in chemistry that helps us understand how atoms interact and form chemical bonds.

The Formula

Electron gain is typically expressed in kJ/mol (kilojoules per mole) and is represented by the following equation:

\[X(g) + e^- \rightarrow X^-(g) + \text{Energy}\]

Where:

• X(g) is a neutral atom in the gas phase
• e- is an electron
• X-(g) is the resulting negative ion
• Energy is the electron affinity (positive if energy is absorbed, negative if energy is released)

Interpretation

• Negative electron gain: Energy is released when an electron is added (exothermic process). This means the atom has a high affinity for electrons.
• Positive electron gain: Energy must be supplied to add an electron (endothermic process). This means the atom has a low affinity for electrons.

Example Calculation

Let's consider the electron gain for chlorine:

\[Cl(g) + e^- \rightarrow Cl^-(g) + (-349 \text{ kJ/mol})\]

The electron gain of chlorine is -349 kJ/mol. The negative sign indicates that energy is released when chlorine gains an electron, making it an exothermic process.

Factors Affecting Electron Gain

• Atomic size
• Nuclear charge
• Electron configuration
• Effective nuclear charge

Understanding electron gain helps chemists predict chemical behavior, reactivity, and the formation of chemical bonds.