A transition element has an electronic configuration of in its oxidation state. What is the atomic n — d and f Block Elements Chemistry Question

💡 Solution & Explanation

If the $+3$ oxidation state has the configuration $[Ar] 3d^4$, it means the neutral atom has $4+3 = 7$ valence electrons beyond the $[Ar]$ core. The first two electrons removed are from the $4s$ orbital, and the third is from the $3d$ orbital. The neutral atom configuration is $[Ar] 3d^5 4s^2$. This corresponds to Manganese ($Mn$), which has an atomic number of $25$.