Arrhenius Theory: according to Arrhenius, acid is one that can donate proton in an aqueous solution, while base is one that can donate hydroxide ion in an aqueous solution.
Bronsted-Lowry Theory: according to Bronsted Lowry, acid is one that can donate protons while base is one that can accept a proton.
1. In first, only C. NH3 can't give hydroxide ion, but can accept a proton so it is a Bronsted-Lowry Base but not an Arrhenius base.
2.In second, as the definition suggested, bronsted base is one that can accept protons and acid is one that can loose protons. so answer is D. Acids lose H+ and bases gain H+.
The aufbau principle, from the German Aufbauprinzip (building-up principle), also called the aufbau rule, states that in the ground state of an atom or ion, electrons fill atomic orbitals of the lowest available energy levels before occupying higher levels.
H2O, also known as water, stands for two hydrogen atoms and one oxygen atom. Hope this helps! ^^
The two sublevels are s and p. These are the main group sublevels