Term: dysprosium (Dy)
Literally meaning: “pertaining to not accessible ”
δυσ-/dys-(=prefix used with a negative sense meaning “difficult”, “bad”, “abnormal”, “misfortune”) > δύω/dyo(=decline) δύση/dysi(=sundown)
> προς/pros(=towards) + ίημι/eemi(=send)
Dysprosium was found in 1886 by French chemist Paul Emile de Boisdaudran (1838-1912) when he separated dysprosium oxide from homium oxide. Boisdaudran isolated dysprosium with a time consuming procedure which involved 32 precipitations leading to its name which means “hard to obtain”.
Dysprosium is a chemical element with atomic number 66 and atomic mass 162,500. It is found only in minerals and never as a free element. It is used in nuclear reactors because is proper to absorb neutrons and for dat6a storing eg compact discs.