The Pauli exclusion principle dictates the 3rd electron must occupy the 2nd energy orbit level; so why does the 5th orbiting electron not occupy the 3rd energy level because electrons have only two possible spins (+/- 1/2-spin).

Is this because electrons can go up to higher energy levels but they choose to pair before going up to a higher energy levels( spin up and spin down)? Once pairing has taken place do they then occupy higher energy levels by first paralleling because it is more efficient to do so?

Sorry to answer your question with a question, but I found your post interesting.

Is this because electrons can go up to higher energy levels but they choose to pair before going up to a higher energy levels( spin up and spin down)? Once pairing has taken place do they then occupy higher energy levels by first paralleling because it is more efficient to do so?

Sorry to answer your question with a question, but I found your post interesting.
It seems similar to the classical idea that atoms don't exist because the moving electron radiate as they move thus loosinng energy and falling into the nucleus,
I wonder if the "zoo" of particles are shards instead of elemental particles. It seems that virtual particles a convenience.. Though the creation from nothing and annihilation are claimed to satisfy conservation of energy; it still seems a specious interpretation.