what are isoelectronic species? give examples.
The correct answer and explanation is:
Isoelectronic species are atoms, ions, or molecules that have the same number of electrons, meaning they share an identical electron configuration. Although these species may differ in their atomic number or charge, the key characteristic is the same number of electrons. The term “isoelectronic” comes from the Greek word “iso,” meaning equal, and “electron,” which refers to the subatomic particles that carry a negative charge.
For example, consider the following isoelectronic species:
- Neon (Ne) – Atomic number 10, electron configuration: 1s² 2s² 2p⁶
- Sodium ion (Na⁺) – Atomic number 11, electron configuration: 1s² 2s² 2p⁶
- Fluoride ion (F⁻) – Atomic number 9, electron configuration: 1s² 2s² 2p⁶
- Magnesium ion (Mg²⁺) – Atomic number 12, electron configuration: 1s² 2s² 2p⁶
In this case, all four species (Ne, Na⁺, F⁻, and Mg²⁺) have 10 electrons, making them isoelectronic with each other. Despite having different nuclear charges (10, 11, 9, and 12 respectively), they all share the same electron configuration of 1s² 2s² 2p⁶, which is the same as that of neon, a noble gas.
Another example can be found in transition metals. For instance, the ions of manganese (Mn²⁺), iron (Fe³⁺), and cobalt (Co²⁺) are isoelectronic with each other, as they all have the same number of electrons and share similar electron configurations.
The concept of isoelectronic species is important in chemistry because it helps scientists understand similarities in chemical behavior. Since these species have the same number of electrons, they often exhibit similar chemical properties, especially in terms of bonding and interactions with other molecules or ions.