Electron-pair intracule (relative motion) h(u) and extracule (center-of-mass motion) d(R) densities are studied for the P-3, D-1, and S-1 multiplet states of five group 14 atoms with p(2) configurations, the S-4, D-2, and P-2 multiplets of five group 15 atoms with p(3) configurations, and the P-3, D-1, and S-1 multiplets of five group 16 atoms with p(4) configurations. For all 15 atoms, it is confirmed that a lower total energy E in a high angular momentum state is always accompanied with the decrease of the electron-nucleus attraction energy V-en which is greater than the increase in the electron-electron repulsion energy V-ee, as discussed in the literature for a few light atoms. In all the cases, the difference in the radial intracule densities 4 pi u(2)h(u) clarifies that for a multiplet with a higher angular momentum, the probability of finding a pair of electrons separated by a short/long distance is larger/smaller, leading to a greater V-ee and a smaller average interelectronic distance [u]. The Fermi hole effect is not important for the relative stability of the multiplets examined. For the multiplets arising from the p(n) electronic configurations, the differences in the radial extracule densities 4 pi R-2 d(R) are found to be almost isomorphic with the corresponding intracule ones: In a multiplet with a high angular momentum, the average center-of-mass radius [R] of an electron pair is always smaller, and two electrons are more likely to be at opposite positions with respect to the nucleus. Accordingly, the valence p orbital in a more stable multiplet is more tight, resulting in a lower electron-nucleus attraction energy V-en for all the 15 atoms.