Give the ground state electron configuration and number of unpaired electrons in a Ru2+ ion. (LO 6.1, 6.2) (a) 3Kr45s2 4d4 0 unpaired electrons (b) 3Kr45s2 4d6 0 unpaired electrons (c) 3Kr44d6 4 unpaired electrons (d) 3Kr45s24d4 4 unpaired electrons

Verified step by step guidance

1. Step 1: Identify the atomic number of the element. The atomic number of Ruthenium (Ru) is 44. This means that a neutral Ruthenium atom has 44 electrons.
2. Step 2: Determine the electron configuration of the neutral atom. The electron configuration of a neutral Ruthenium atom is [Kr]5s^24d^6.
3. Step 3: Adjust for the ion charge. The Ru2+ ion has lost 2 electrons. When electrons are removed, they are taken from the outermost shell first. So, the electron configuration of Ru2+ would be [Kr]4d^4.
4. Step 4: Determine the number of unpaired electrons. In the 4d subshell, there are 4 electrons. According to Hund's rule, each orbital in a subshell is singly occupied before any orbital is doubly occupied. So, there are 4 unpaired electrons in the Ru2+ ion.
5. Step 5: Match the electron configuration and number of unpaired electrons with the given options. The correct answer is (d) 3Kr45s24d4 4 unpaired electrons.

Key Concepts

Electron Configuration

Electron configuration describes the distribution of electrons in an atom's orbitals. For transition metals like ruthenium (Ru), the configuration is determined by the Aufbau principle, Hund's rule, and the Pauli exclusion principle. The ground state configuration of an atom is the lowest energy arrangement of its electrons, which is crucial for understanding its chemical properties and reactivity.

Transition Metal Ions

Transition metals can lose different numbers of electrons when forming ions, typically from their outermost s and d orbitals. For Ru, which has an atomic number of 44, the Ru2+ ion indicates that it has lost two electrons. Understanding how to derive the electron configuration of transition metal ions is essential for predicting their behavior in chemical reactions and their magnetic properties.

Unpaired Electrons

Unpaired electrons are those that occupy an orbital alone rather than in pairs. The number of unpaired electrons in an atom or ion is significant because it influences the magnetic properties of the species; atoms with unpaired electrons are typically paramagnetic. Identifying unpaired electrons is crucial for understanding the electron configuration and predicting the chemical and physical behavior of elements.