What is the ground-state electron configuration for the Mg²⁺ ion? (LO 6.1) (a) 1s²2s²2p⁶ (b) 1s²2s²2p⁶3s² (c) 1s²2s²2p⁶3s²3p² (d) 1s²2s²2p⁶3s²3p⁶

Verified step by step guidance

1. Step 1: Identify the atomic number of magnesium (Mg), which is 12. This means a neutral Mg atom has 12 electrons.
2. Step 2: Write the electron configuration for a neutral Mg atom: 1s^2 2s^2 2p^6 3s^2.
3. Step 3: Recognize that Mg^2+ indicates the magnesium ion has lost 2 electrons.
4. Step 4: Remove 2 electrons from the outermost shell (3s orbital) of the neutral Mg electron configuration.
5. Step 5: The resulting electron configuration for Mg^2+ is 1s^2 2s^2 2p^6.

Key Concepts

Electron Configuration

Electron configuration describes the distribution of electrons in an atom's orbitals. It follows the Aufbau principle, which states that electrons fill the lowest energy orbitals first. The notation includes subshells (s, p, d, f) and the number of electrons in each subshell, providing insight into the atom's chemical properties and reactivity.

Ionization and Charge

Ionization refers to the process of removing electrons from an atom, resulting in a charged ion. For magnesium (Mg), which has an atomic number of 12, losing two electrons to form Mg²⁺ means it has a total of 10 electrons. Understanding how ionization affects electron configuration is crucial for determining the ground-state configuration of ions.

Ground-State Configuration

The ground-state configuration is the lowest energy arrangement of electrons in an atom or ion. For ions like Mg²⁺, this configuration reflects the stable state after ionization. It is essential to identify the correct electron configuration to predict the ion's behavior in chemical reactions and its interactions with other elements.