4 because s,p, d, and f are all in the 4th shell as subshells Levels Sublevels. n=4 4s, 4p, 4d, 4f. n=3 3s, 3p, 3d. n=2 2s, 2p. n=1 1s.
Boron is in period 2 of the periodic table and therefore has 2 orbital shells.
1 or 2 or 3 or 4 or 5
47 positive
3rd to onward all energy levels have 5 d-orbitals their name assign are dxy,dxz,dyz,d(x2 - y2) and dz2