Final answer:
Mozart achieves an airy feel in the development of the second movement of his Symphony No. 40 in G minor through light orchestration, creating a sense of openness and weightlessness.
Step-by-step explanation:
Mozart creates an airy feel in the development of the second movement of his Symphony No. 40 in G minor primarily through light orchestration. This technique involves employing fewer instruments and a more delicate touch in the musical arrangement, which contrasts with the denser textures that might be used in other sections or movements. Unlike dissonance, which could provide a sense of tension, or minimal dynamics, which would play with volume, light orchestration gives the music a feeling of openness and weightlessness. Moreover, since the tempo of this movement is not particularly fast, it contributes less to the airy feel than the sparse orchestration does.