Etymology

Prot(o)- ‎(“proto-”) +‎ actínio ‎(“actinium”), from Ancient Greek ἀκτίς ‎(aktís, “ray”).

Pronunciation

• (Brazil) IPA^(key): /pɾo.tak.ˈt͡ʃi.ni.u/, /pɾo.tak.ˈt͡ʃi.nju/, /pɾo.ˌta.ki.ˈt͡ʃi.nju/
• (South Brazil) IPA^(key): /pɾo.tak.ˈt͡ʃi.ni.o/, /pɾo.tak.ˈt͡ʃi.njo/, /pɾo.ˌta.ki.ˈt͡ʃi.njo/
• Hyphenation: pro‧tac‧tí‧ni‧o