Let's see, there's the standard four, and if you're a chemist, you may come across 'vanadous', 'indous', 'rubidous', 'iridous', 'molybdous', 'scandous', 'palladous', 'rhodous', and perhaps 'radous' (assuming anyone works with compounds of radium). 'Molybdous' comes up fairly frequently; 'iodous' might seem to be a legitimate word as well, but its regular valence is -1, and you can't have one smaller than that. However, an iodine compound with a -2 valence is referred to as 'periodic'!

So what's the longest word you can type with the left hand on the Dvorak keyboard? I get as far as 5, and 3 with the right hand (if you count crossword-clue words :))

--
Trevor Green
"Military justice is to justice what military music is to music."

--
Trevor Green
"Military justice is to justice what military music is to music."