Consider an ideal monatomic gas, but one for which the atom has two internal energy states, one

Question:

Consider an ideal monatomic gas, but one for which the atom has two internal energy states, one an energy ∆ above the other. There are N atoms in volume V at temperature τ. Find the
(a) Chemical potential;
(b) Free energy;
(c) Entropy;
(d) Pressure;
(e) Heat capacity at constant pressure.