Question

get it? explain how to write the noble-gas notation for an element. what is the noble-gas notation for calcium?

Explanation:

Noble - gas notation simplifies electron - configuration writing. First, find the noble gas with an atomic number less than the element's. Then, write the noble - gas symbol in brackets and add the remaining electrons' configuration. For calcium (atomic number \(20\)), the noble gas before it is argon (atomic number \(18\)). The remaining \(2\) electrons go into the \(4s\) orbital.

Answer:

The noble - gas notation for calcium is \([\text{Ar}]4s^{2}\).