SCIENCE PHOTO LIBRARY SCIENCE PHOTO LIBRARY
Zirconium (Zr). Diagram of the nuclear composition and electron configuration of an atom of zirconium-90 (atomic number: 40), the most common isotope of this element. The nucleus consists of 40 protons (red) and 50 neutrons (blue). Zirconium is a transition metal in group 4, period 5, and the d-block of the periodic table. It has a melting point of 1855 degrees Celsius. The trends across the transition metals are due to electrons filling an inner d-subshell (here, within the 4th ring), shielding the outer electrons from the increasing nuclear charge.
Model release not required. Property release not required.