the united states emitted 19.5 million of nitrogen oxides (NO) into the atmosphere in 1987. One metric ton (1t) equals 1,000kg. How many kilograms of NO were emitted to the atmosphere in the united states during 1987?
"19.5 million" what? If they were in metric tons, just multiply 19.5 million by 1000.
I hope this helps. Thanks for asking.