Why is Carbon 12 the only atom witha relative atomic mass which is an exact whole number?
Because, by convention, chemists have set it to be exactly 12 and relate the mass of every other isotope of every other element to that one. If chemists had decided to use hydrogen as the benchmark, then that would be exactly 1 instead of 1.008. But they didn’t, so it isn’t. Well, whoever gave this the thumbs down is deluded. I never said it was exactly 12 for carbon. The question mentioned carbon-12. I was responding to the question as asked and was therefore totally accurate and correct in my reply. You ought to read the question properly before jumping in with both feet in your mouth.
