Diagram of the nuclear composition, electron configuration, and valence orbitals of an atom of barium-137 (atomic number: 56), an isotope of this element. The nucleus consists of 56 protons (blue) and 81 neutrons (red). 56 electrons (white) successively occupy available electron shells (rings). The stability of an element's outer (valence) electrons determines its chemical and physical properties. Barium is an alkaline earth metal in group 2, period 6, and the s-block of the periodic table. It is extremely reactive and burns with a green flame. Barium compounds are used as X-ray contrast mediums for the digestive system. | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Clarivan, Carlos |
Bildgröße: | 4724 px × 3811 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |