UNSR138 OFFICIAL

unsur 138Name of the isotope: Cesium-138; Cs-138 Symbol: 138 Cs or 138 55 Cs Mass number A: 138 (= number of nucleons) Atomic number Z: 55 (= number of protons) Neutrons N: 83 IsotopicUnsur 138, also known as Eka-Lawrencium, is a synthetic element with the atomic number 138. It was first predicted as part of the actinide series in the 1940s and was officially