What is the correct electron configuration for Antimony (Sb)?

Antimony (Sb) has an atomic number of 51, which means it has 51 electrons to accommodate in its electron configuration. The order of filling orbitals is determined by the Aufbau principle, which states that electrons fill lower-energy orbitals before higher-energy ones.

The electron configuration starts with the noble gas preceding antimony in the periodic table, which is Krypton (Kr), having an electron configuration of [Kr]. After Kr, the next electrons fill the 5s orbital, which can hold 2 electrons: 5s². Following this, the 4d subshell is filled, which can hold up to 10 electrons: 4d¹⁰.

Finally, antimony has 3 additional electrons that fill the 5p subshell. Thus, the complete electron configuration for antimony is [Kr] 5s² 4d¹⁰ 5p³. This configuration accurately represents the distribution of all 51 electrons in the atom.

The other configurations listed in the choices either have too many or too few electrons in the 5p subshell. Some suggest an incorrect filling of the 5p orbital, which adds or subtracts electrons that do not align with the atomic number of