Final answer:
Electron configurations describe the arrangement of electrons in an atom or ion based on energy levels and subshells. The configurations for Ca²⁺, Br⁻, Sb, and Ni²⁺ provide the specific arrangement of electrons considering their charges.
Step-by-step explanation:
To write the electron configurations for atoms and ions, we must consider the number of electrons and apply the Aufbau principle, which states that electrons fill orbitals starting with the lowest energy level first. Here are the electron configurations:
- Ca²⁺: 1s² 2s² 2p⁶ 3s² 3p⁶.
- Br⁻: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶.
- Sb (Antimony): 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 5s² 4d¹⁰ 5p³.
- Ni²⁺: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁸.
Ion-specific configurations typically involve the removal or addition of electrons from the neutral atom's configuration in order to achieve the charge stated.