How was Harold Clayton Urey awarded the Noble Prize?

Brickwedde’s initial sample was evaporated at 20 K (253.2 °C; 423.7 °F) and 1 standard atmosphere (100 kPa) of pressure. They were surprised to see that there was no evidence of enrichment. A second sample was then created by Brickwedde, and it evaporated at 14 K (259.1 °C; 434.5 °F) under a pressure of 53 mmHg (7.1 kPa). The Balmer lines for heavy hydrogen were seven times stronger in this sample. Urey, Murphy, and Brickwedde collaborated to publish the paper that announced the discovery of heavy hydrogen, later named deuterium, in 1932.  Harold Clayton Urey won the Nobel Prize in Chemistry in 1934 “for his discovery of heavy hydrogen.”