Final answer:
The noble gas electron configuration of bismuth is [Rn] 5f14 6d10 7s2 6p3. It reflects the inert pair effect with a stable 7s2 pair that is reluctant to participate in bonding.
Step-by-step explanation:
The noble gas electron configuration of bismuth (Bi), which is the heaviest member of group 15 with an atomic number of 83, can be determined by following the order of the periodic table to fill the electron orbitals up to the element's atomic number while using the previous noble gas to simplify the notation. The noble gas configuration is a shorthand notation that includes the elemental symbol of the last noble gas prior to that element, followed by the configuration of the remaining electrons. As bismuth is in group 15, it shares some properties with nitrogen and phosphorus, which have general configurations ending in s2p3.
To determine bismuth's noble gas electron configuration, we need to consider that the previous noble gas before bismuth is radon (Rn), and the electron configuration for radon ends at the 6p6 level. Beyond radon, we continue to fill the 6d and the 7s orbitals, and finally, the 6p orbitals. Bismuth ends up with the following electron configuration: [Rn] 5f14 6d10 7s2 6p3. It clearly exhibits the inert pair effect with its two electrons in the 7s orbital, which are stable and do not participate readily in chemical bonding.