Question

A metal ion with a net +3 charge has five electrons in the \(3 d\) subshell. Identify the metal

Short answer

The metal is Manganese (Mn).

Step-by-step solution

Understand the Information

We are given a metal ion with a net +3 charge and it has five electrons in the \(3d\) subshell. Our task is to identify the element.

Determine the \(3d\) Electron Configuration

The given ion has five electrons in the \(3d\) subshell, which means the electronic configuration of this metal ion in its ionized state is \([Ar] 3d^5\).

Account for the +3 Charge

The ion has a +3 charge, which means it has lost 3 electrons compared to its neutral state. To find the neutral atom, we need to add these 3 electrons back to the configuration \([Ar] 3d^5\). This results in \([Ar] 3d^5 4s^2\).

Identify the Element

The configuration \([Ar] 3d^5 4s^2\) corresponds to the element Manganese \(Mn\), which has an atomic number of 25 in its ground state.

Key concepts

Metal Ions

Metal ions are charged atoms or molecules that originate from metals. When a metal loses electrons, it becomes positively charged; these are known as cations. The charge is often indicated by a plus sign. For example, when a sodium atom loses an electron, it becomes Na⁺.
In the case of the exercise, we deal with a metal ion that has a net +3 charge. This signifies the metal originally had three more electrons, which it lost, becoming a cation. The charge result indicates how many electrons are lost from the neutral atom. Understanding metal ions is essential when determining ions in solution and impacts chemical reactivity.

3d Subshell

The 3d subshell is a key concept in the study of electron configurations for transition metals. It can hold up to 10 electrons, following the rule of filling up from lower to higher energy levels, beginning from the 1s up to the 3d, and eventually the 4s and so on. Electrons in d subshells play a critical role in the chemical properties of elements, especially in transition metals.
In the exercise, we consider an ion with five electrons present in the 3d subshell, noted as \(3d^5\). The presence of these electrons influences both the element's behavior and its identifiable characteristics. Since transition elements usually involve their d subshells, understanding their filling order and number of electrons can be crucial for element identification.

Mn Identification

Identifying an element, such as Manganese ( Mn), involves understanding its electron configuration and its ionized states. For this exercise, we first account for a positive charge in the ion and then reverse to find the neutral atom's configuration. The \(3d^5 4s^2\) pattern reinstates the neutral ground state of the atom, helping us pinpoint terrestrial markers.

• The ion is initially given in a 3+ charged state, indicating it lost three electrons.
• To find the neutral configuration, \(3d^5 4s^2\) is resolved from steps taken in tracing its electron configuration.
• The interpretation of the electronic configuration directly leads us to Mn with atomic number 25.

This systematic breakdown of these concepts is fundamental for accurate identification.

Atomic Number

The atomic number of an element is a fundamental property representing the number of protons in the nucleus of an atom. This attribute not only defines the element but also organizes elements in the periodic table. Since the number of protons equals the number of electrons in a neutral atom, the atomic number is crucial for establishing its electronic configuration.
For Manganese ( Mn), the atomic number 25 means it has 25 protons and, in its neutral state, 25 electrons. In the exercise, identifying the ion's electronic setup eventually leads us to recognize Mn's atomic number, reinforcing its unique elemental identity and its place in the periodic table. The atomic number for any element directly correlates with its distinct properties and its role in chemical reactions.