caesium133

Moreover, the nucleus of caesium-133 has a nuclear spin equal to 7/2. The simultaneous presence of electron spin and nuclear spin leads, by a mechanism called ...

2014年10月4日 — Caesium is the chemical element that has literally redefined time. It ... caesium-133 atom. A diagram of an atom. Image ...

Note that this frequency occurs when the Cesium-133 atom is in isolation at absolute zero temperature; in reality corrections for this are necessary. Still, the ...

Cesium-133 is the only natural isotope (100% natural abundance). Cesium has no known biological role, but may substitute for potassium and so is relatively ...

It is produced by irradiating the stable isotope cobalt-59 with neutrons in a nuclear reactor. Cobalt-60 is used in the inspection of materials to reveal ...

2021年5月14日 — The second, symbol s, is the SI unit of time. It is defined by taking the fixed numerical value of the caesium frequency ΔvCs, the unperturbed ...

2021年8月27日 — Cesium-133 is used for the definition of the second, because one of the first practical atomic clocks was based on it. However, ...

使用銫標准定義的第一組單位與時間有關，第二組單位於1967年定義為“9 192 631 770週期持續時間被定義為”。“Cesium-133原子”的意思是： 1 秒, s, = 9,192,631,770 ΔtCs1 ...

131Cs, 人造, 9.689 天 · ε, 0.358, Xe. 133Cs, 100%, 穩定，帶78粒中子. 134Cs, 人造, 2.0650 年 · ε, 1.235, Xe · β, 2.059, Ba. 135Cs, 痕量, 1.33×106 年 · β, 0.269 ...