2804            |    Hydrogen, rare gases and other non-metals.
2804.10.00   - Hydrogen
2804.21.00     -- Argon
2804.29.00     -- Other
2804.30.00   - Nitrogen
2804.40.00   - Oxygen
2804.50.00   - Boron; tellurium
2804.61.00     -- Containing by weight not less than 99.99% of silicon
2804.69.00     -- Other
2804.70.00   - Phosphorus
2804.80.00   - Arsenic
2804.90.00   - Selenium