60.0 MB (922.6 KB compressed)
4579 x 4579 pixels
38.9 x 38.9 cm ⏐ 15.3 x 15.3 in (300dpi)
SCIENCE PHOTO LIBRARY SCIENCE PHOTO LIBRARY
Promethium (Pm). Diagram of the nuclear composition and electron configuration of an atom of promethium-147 (atomic number: 61), the most common isotope of this element. The nucleus consists of 61 protons (red) and 86 neutrons (blue). 61 electrons (green) bind to the nucleus, successively occupying available electron shells (rings). Promethium is a lanthanide in period 6, and the f-block of the periodic table. It melts at 1042 degrees Celsius. The trend across the lanthanide series arises from the failure of electrons filling an inner f-subshell (here, within the 4th ring) to shield outer electrons from increasing nuclear charge.
Model release not required. Property release not required.