The principal quantum number (n) describes the size of the orbital. Orbitals for which n = 2 are larger than those for which n = 1, for example.
Theoretical Yield = 1.93g H₂CO₃, %yield = 94.3%
Explanation:
Knowing that NaHCO₃ is the only reactant in the equation, it's easily the limiting reactant. Convert the given mass of NaHCO₃ to mass of H₂CO₃ through stoichiometry. The actual given yield of H₂CO₃ is 1.82g, so you just use the percent yield equation.