Periodic cairt wi electron shells

In chemistry and atomic pheesics, an electron shell, or a principal energy level, mey be thocht o as an orbit follaed bi electrons aroond an atom's nucleus. The closest shell tae the nucleus is cried the "1 shell" (an aa cried "K shell"), follaed bi the "2 shell" (or "L shell"), then the "3 shell" (or "M shell"), an sae on farther an farther frae the nucleus. The shells correspond wi the principal quantum nummers (n = 1, 2, 3, 4 ...) or are labeled alphabetically wi letters uised in the X-ray notation (K, L, M, …).