— rubidic , adj.
/rooh bid"ee euhm/ , n. Chem.
a silver-white, metallic, active element resembling potassium, used in photoelectric cells and radio vacuum tubes. Symbol: Rb; at. wt.: 85.47; at. no.: 37; sp. gr.: 1.53 at 20°C.
[ 1860-65; rubid ( us ) red (in allusion to the two red lines in its spectrum) + -ium -IUM ]