That seems like a statement more than a question. Where's the question?
the determination of the age or date of organic matter from the relative proportions of the carbon isotopes carbon-12 and carbon-14 that it contains. The ratio between them changes as radioactive carbon-14 decays and is not replaced by exchange with the atmosphere.
Answer:
12 Neutrons
Explanation:
So the mass of sodium is 22.990. You round it up to get 23(as stated in the problem). So, <em>what exactly is atomic mass?</em>
Atomic Mass is the total amount of neutrons and protons added up to form a total mass. So when you subtract 23-11 you get 12 Neutrons.
<u>Tip: </u>Don't know if you need this but-
The neutrons and protons are typically close in number (unless it's an isotope). So say that you subtract and the numbers of protons and neutrons aren't close at all. Well if that's the case, it's probably wrong.
hope this helps!!