Write the electron configuration for each ion. a. Cl^-

Verified step by step guidance

1. Step 1: Identify the atomic number of the neutral atom. The atomic number of Chlorine (Cl) is 17, which means a neutral chlorine atom has 17 electrons.
2. Step 2: Determine the charge of the ion. In this case, the ion is Cl^-, which means it has gained one electron.
3. Step 3: Add the number of gained or subtract the number of lost electrons from the atomic number to find the total number of electrons in the ion. Since Cl^- has gained one electron, it has 18 electrons in total.
4. Step 4: Write the electron configuration for the neutral atom first. The electron configuration of a neutral chlorine atom (17 electrons) is 1s² 2s² 2p⁶ 3s² 3p⁵.
5. Step 5: Add the extra electron to the highest energy level (n=3). The electron configuration of Cl^- is 1s² 2s² 2p⁶ 3s² 3p⁶.

Key Concepts

Electron Configuration

Electron configuration describes the distribution of electrons in an atom or ion's orbitals. It is represented using a notation that indicates the energy levels and sublevels occupied by electrons. For example, the electron configuration of a neutral chlorine atom (Cl) is 1s² 2s² 2p⁶ 3s² 3p⁵, which shows how electrons are arranged in various energy levels.

Ionic Charge

Ionic charge refers to the electrical charge that an atom or molecule acquires when it gains or loses electrons. Anions, like Cl⁻, are negatively charged ions formed when an atom gains one or more electrons. This additional electron alters the electron configuration, resulting in a more stable arrangement, often resembling that of the nearest noble gas.

Noble Gas Configuration

Noble gas configuration is a shorthand notation for electron configurations that highlights the stability of noble gases, which have full outer electron shells. For chlorine, gaining an electron to form Cl⁻ results in the electron configuration resembling that of argon (Ar), which is 1s² 2s² 2p⁶ 3s² 3p⁶. This configuration indicates a stable, filled outer shell.