Question

Explain what is meant by a noble gas core. Write the electron configuration of a xenon core.

Short answer

A noble gas core refers to the core electron configuration of an atom, which mirrors that of the nearest noble gas with a lower atomic number. The electron configuration of a xenon core is \([Kr] 5s^2 4d^{10} 5p^6\).

Step-by-step solution

Understanding What a Noble Gas Core Is

A noble gas core refers to the inner electrons of an atom, which have the same electron configuration as the nearest noble gas with lower atomic number. Nobel gases are chemically stable, and hence their electron configurations are often referred to as 'noble gas cores'.

Writing the Electron Configuration of a Xenon Core

Xenon is a noble gas, and it has an atomic number of 54. When writing the electron configuration, we use the principle of building-up order or the Aufbau principle. Xenon's electron configuration is \(1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^6 5s^2 4d^{10} 5p^6\). This can be simplified by referring to the previous noble gas, Krypton (Kr), which saves the task of writing the complete electron structure that is identical to another noble gas. So, the configuration for Xenon is \([Kr] 5s^2 4d^{10} 5p^6\), where [Kr] represents the electron configuration of Krypton.