Question

question 4 (1 point) which of the following is the correct noble gas notation for iron (fe)? a ar 4s^13d^5 b ar 4s^23d^6 c ar 4s^24d^6 d ar 4s^24d^5

Explanation:

Iron (Fe) has an atomic number of 26. The noble - gas core before iron is argon (Ar) with 18 electrons. The remaining 8 electrons fill the 4s and 3d orbitals. According to the Aufbau principle, the 4s orbital fills before the 3d orbital. The 4s orbital can hold 2 electrons and the 3d orbital can hold 6 electrons for iron, resulting in the electron configuration [Ar] 4s²3d⁶.

Answer:

B. [Ar] 4s²3d⁶