28041000

HYDROGEN

28042100

ARGON (RARE GASES)

28042910

HELLIUM

28042990

OTHR RARE GASES OTHER THAN ARGON & HELLIUM

28043000

NITROGEN

28044010

OXYGEN,MEDICINAL GRAPE

28044090

OTHER OXYGEN

28045010

BORON

28045020

TELLURIUM

28046100

SILICON CONTNG MORE THAN99.99% BY WT OF SILICON

28046900

OTHER SILICON

28047010

PHOSPHORUS BLACK

28047020

PHOSPHORUS RED

28047030

PHOSPHORUS WHITE OR YELLOW

28048000

ARSENIC

28049000

SELENIUM