Surat Al-A’raf Ayat

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 IsotopicRecently, Unsur 138 is known as a placeholder name for a element which could founder the extended periodic table. The atomic number 138 shows that it can act like