Air (79 percent N2 and 21 percent O2) is heated to 2000 K at a constant pressure

Question:

Air (79 percent N2 and 21 percent O2) is heated to 2000 K at a constant pressure of 2 atm. Assuming the equilibrium mixture consists of N2, O2, and NO, determine the equilibrium composition at this state. Is it realistic to assume that no monatomic oxygen or nitrogen will be present in the equilibrium mixture? Will the equilibrium composition change if the pressure is doubled at constant temperature?