English

Noun

eka-protactinium ‎(uncountable)

1. Unbitrium (Ubt), an unsynthesized chemical element with atomic number 123.
2. Unquadunium (Uqu), an unsynthesized chemical element with atomic number 141.

Usage notes

• The prefix eka- is used to name predicted but undiscovered elements by specifying the known element above them in the same group of the periodic table.