Element Actinium, Ac, Actinide or Actinoid. After which the latter name was confirmed. Is a member of actinide. Isotopes with mass numbers from 221 to 230 are known. The most long-lived of them is. However, comparing with other elements actinium abundance. Is extremely small, 6x10.

Element Caesium, Cs, Alkali Metal. Had undoubtedly been examined before, but had been mistaken by C. Plattner for potassium salts, meanwhile it was consisting of hydrous caesium. Pisani revealed it on the analysis of pollux in 1864.

Element Yttrium, Y, Transition Metal. As an element of the 3. Group in periodic system, does not belong to the group rare earth metals; however the history of its discovery is closely connected with rare earth elements. A lustrous black color mineral. Ekeberg extracted an earth from this mineral and named it yttria. 45 years later Mosander extracted yttrium.

Tutti i coupon della tua città! CLICCA MI PIACE PER VEDERE LA TV.

This is the place where you can personalize your profile! By moving, adding and personalizing widgets.