Hi, I’m sure this has probably been asked before but I can’t find any answers.
I am doing GCSE AQA science and in chemistry the teacher handed out periodic tables, the ones I and a few others got were A-level ones rather than GCSE.
These ones had the relative atomic mass under each symbol. This has really confused me, as I thought that the mass number was protons+neutrons and the atomic number was both protons and electrons. While the relative atomic mass is sort of the average mass of all isotopes of that element compared to carbon 12.
The teacher has been treating the relative atomic mass as the same as the mass number and using it to work out how many neutrons. I can’t understand this and Google just repeats the same useless things telling me what each different name means.
So how are they working the same if they are totally different numbers from totally different things?
Thanks for any help!