Final answer:
The ground state electron configuration for rubidium (Rb) is [Kr]5s1, which denotes one valence electron in the 5s orbital, added to the noble gas configuration of krypton.
Step-by-step explanation:
The student asked for the ground state electron configuration for rubidium (Rb), which has 37 electrons. To provide the simplified or abbreviated electron configuration, we reference the nearest noble gas with fewer electrons than Rb, which is krypton (Kr), and continue from there. Rubidium is the first element in the fifth period after krypton, so we add one electron in the next available subshell, which is the 5s subshell.
The ground state electron configuration for Rb can be written as [Kr]5s1. This notation indicates that Rb has the same electron configuration as krypton with the addition of one electron in the 5s orbital. This is a common approach known as the noble gas configuration for simplifying electron notation in atoms with many electrons.
Rubidium, being an alkali metal, has a single valence electron in its outermost shell, which is characteristic of its group in the periodic table. The valence electron is important in chemical reactions as it can be easily lost, making rubidium a highly reactive element.