Express 26/9

[Donald Duck]

10a/ a yellow water-soluble vitamin of the B complex,essential for the carbonhydrate metabolism of cells (10) ??b?t?a?i? 4d/ any of the unreactive elements helium, neon, argon, krypton, radon and xenon ((4,3) R??? gas

[Davao]

Tried answering a while ago but power here in Philippines went down. Hope I get this away ok.
I think 10 across is Riboflavin and 4 down Noble gas. haven't got the crossword here to look at though.

[Donald Duck]

thanks for your help

[redman41]

Riboflavin
Rare Gas

[Donald Duck]

thanks for your answer Redman. sorry for being late in acknowledging but I really am at a loss as to how to access this Q & A site these days. Can you enlighten?