The Ksp of FeCO3 is 3.13×10−11, the Ksp of Fe(OH)2 is 4.87×10−17, and the Ksp of FeF2 is 2.36×10−6. If a solution contained CO2−3, OH−, and F− ions, each at a concentration of 0.1 M, and the Fe2+ ion concentration is slowly increased from a trace amount, which of the salts would precipitate first?

if two electrons have the same n, the same ℓ, and the same ml, then they are in the same orbital. the pauli exclusion principle states that no two identical fermions (a fancy word for electrons and other subatomic particles like electrons) may occupy the same quantum state in an atom simultaneously.

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).