Question

Is it possible for the atoms of one element to be isoelectronic with the atoms of another element? Explain.

Short answer

Yes, atoms of different elements can be isoelectronic, usually when they form ions.

Step-by-step solution

Understanding Isoelectronic

The term 'isoelectronic' refers to atoms, ions, or molecules having the same number of electrons or the same electronic structure. This means their electron configuration should be identical.

Identifying Electron Configuration

To determine if two different atoms can be isoelectronic, we need to consider the electron configuration of each atom. Typically, atoms will need to gain or lose electrons (forming ions) to become isoelectronic.

Looking at Atoms and Ions

For example, consider the atoms of Nitrogen ( ext{N}) and Oxygen ( ext{O}). The neutral Nitrogen atom has 7 electrons, and the neutral Oxygen atom has 8 electrons. In their ionic forms, ext{N}^{3-} and ext{O}^{2-}, both can have the same electron configuration as Neon ( ext{Ne}), which is ext{1s}^2 ext{2s}^2 ext{2p}^6.

Conclusion

It is possible for atoms of different elements to be isoelectronic, but this typically occurs when the atoms form ions by gaining or losing electrons. For instance, ext{N}^{3-}, ext{O}^{2-}, and ext{F}^{-} ions are all isoelectronic with Neon ( ext{Ne}).

Key concepts

Electron Configuration

Electron configuration is the arrangement of electrons in an atom's electron shells or orbitals. Each atom has a unique electron configuration based on the number of electrons it possesses. Electrons fill available orbitals in a specific order following the principles of quantum mechanics. This order is guided by the Aufbau principle, Hund's rule, and the Pauli exclusion principle. These principles mean that:

• Electrons fill the lowest energy orbitals first (Aufbau principle).
• Electrons will pair in an orbital only when all orbitals at the same energy level contain one electron each (Hund's rule).
• No two electrons can have the same set of quantum numbers, meaning each electron in an atom must have unique characteristics (Pauli exclusion principle).

An example is the noble gas Neon, which has a completely filled set of energy levels: \(1s^2 2s^2 2p^6\).
This configuration is stable and non-reactive.

Ions

Ions are atoms or molecules that have gained or lost one or more electrons, resulting in a net electrical charge. This charge can be positive or negative:- **Cations:** Positive ions formed by the loss of electrons.- **Anions:** Negative ions formed by gaining electrons.The loss or gain of electrons occurs so that the ion achieves a more stable electron configuration, often resembling that of the nearest noble gas. For instance, when sodium (Na) loses one electron, it becomes \(\text{Na}^+\) and achieves the electron configuration of neon.
Similarly, when chlorine (Cl) gains one electron, it becomes \(\text{Cl}^-\), also mimicking the electron configuration of a noble gas.

Atomic Structure

The atomic structure is composed primarily of three subatomic particles: protons, neutrons, and electrons. Protons and neutrons reside in the nucleus at the center of the atom, while electrons orbit in electron shells around the nucleus. - **Protons** are positively charged particles. - **Neutrons** have no charge (neutral). - **Electrons** are negatively charged particles that determine chemical reactivity and bonding. The overall charge of an atom depends on the balance of protons and electrons. A neutral atom has an equal number of protons and electrons.
When atoms form ions, they alter this balance, thereby changing the electron configuration and stability of the atom.

Electron Gain and Loss

Atoms can gain or lose electrons to achieve a stable electron configuration. This process is crucial for forming chemical compounds and is often driven by the need to achieve the noble gas electron configuration.- **Electron gain** results in anions, as seen when oxygen gains two electrons to become \(\text{O}^{2-}\).- **Electron loss** results in cations, such as sodium losing one electron to become \(\text{Na}^+\).The electron gain or loss is dictated by the element's position in the periodic table and its tendency to reach the stable electron configuration of the nearest noble gas. This results in elements forming ions with specific charges to become isoelectronic with noble gases, as oxygen and nitrogen do with neon.