Hlau Cesium (Cs)
Cov khoom yooj yim
Cesium yog ib hom hlau kub mos mos uas muaj qhov nyuaj ntawm Mohs tsuas yog 0.2 xwb, ua rau nws yog ib hom hlau mos mos tshaj plaws. Nws muaj qhov melting point qis heev (28.5°C) thiab tuaj yeem nyob hauv cov kua thaum lub caij ntuj sov kub. Vim nws cov tshuaj lom neeg ua haujlwm ntau heev, cesium yuav oxidize sai sai thiab nws tus kheej hlawv hauv huab cua, thiab ua rau dej tawm, tso hydrogen thiab tawg, yog li nws yuav tsum khaws cia rau hauv cov roj inert lossis qhov chaw nqus tsev.
Kev tshawb nrhiav thiab kev muab npe
Xyoo 1860, tus kws tshuaj German Robert Bunsen thiab tus kws kho mob Gustav Kirchhoff tau siv cov thev naus laus zis los tshuaj xyuas spectral los tshawb pom cesium hauv cov dej ntxhia thawj zaug. Vim yog cov kab xiav ci ntsa iab hauv nws cov spectrum, lawv tau muab nws lub npe raws li lo lus Latin "caesius" (txhais tau tias "xiav ntuj").
Cov Ntawv Thov Tseem Ceeb
Cesium ua lub luag haujlwm tseem ceeb hauv kev siv tshuab niaj hnub no:
-Lub moos atomic: Lub zaus hloov pauv hyperfine ntawm cesium-133 atoms yog siv los txhais "thib ob" hauv International System of Units (SI), nrog qhov tseeb tsawg dua 1 vib nas this rau kaum lab xyoo. Nws yog siv dav hauv GPS, kev sib txuas lus satellite thiab cov txheej txheem kev lag luam nyiaj txiag.
Kev lag luam roj av: Cesium formate (CsCOOH) yog cov kua dej ua haujlwm siab uas tuaj yeem ruaj khov nyob rau hauv qhov kub thiab txias thiab qhov siab, txhim kho kev ua haujlwm ntawm kev khawb qhov tob.
Kev siv tshuab photoelectric: Cesium rhiab heev rau lub teeb thiab yog cov khoom siv tseem ceeb ntawm cov raj photoelectric, cov khoom siv infrared thiab cov khoom siv pom kev hmo ntuj.
Kev kho mob thiab kev tshawb fawb txog kev tshawb fawb: Cov isotope radioactive cesium-137 yog siv rau kev kho mob qog noj ntshav, thaum cov isotope ruaj khov yog siv rau kev tshawb fawb txog cov kab mob hauv lub cev.
Cov lus tseeb thiab kev cov nyom lom zem
Cov ntsiab lus ntawm cesium hauv lub ntiaj teb lub plhaub yog qis heev (kwv yees li 3 feem ib lab), thiab nws feem ntau yog rho tawm los ntawm cov khoom siv tsis tshua muaj kuab paug, yog li nws kim heev. Vim nws muaj kev ua haujlwm siab, nws feem ntau khaws cia rau hauv cov roj av lossis kaw rau hauv cov iav ampoules hauv chaw soj nstuam.
Xaus lus
Txawm hais tias cov hlau cesium tsis paub zoo li kub thiab nyiaj, nws ua lub luag haujlwm tseem ceeb hauv kev ntsuas lub sijhawm, kev txhim kho lub zog thiab kev siv tshuab siab heev. Nws cov haujlwm hnyav thiab cov khoom siv atomic meej ua rau nws yog tus choj tseem ceeb txuas lub ntiaj teb me me thiab cov ntawv thov macroscopic, thiab txuas ntxiv txhawb kev nce qib ntawm tib neeg kev tshawb fawb thiab thev naus laus zis.