Six Electrons Are in a Two-Dimensional Square Potential Energy Well

Multiple Choice

Six electrons are in a two-dimensional square potential energy well with sides of length L.The potential energy is infinite at the sides and zero inside.The single-particle energies are given by where n_x and n_y are integers.If a seventh electron is added to the system when it is in its ground state the least energy the additional electron can have is:

A) 2 (h²/8mL²)
B) 5 (h²/8mL²)
C) 8 (h²/8mL²)
D) 10 (h²/8mL²)
E) 13 (h²/8mL²)