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So, what is this number really? the mass of one mol of the element or the sum of protons + neutrons? The number is the molar mass expressed in g/mol, i.e. stripped off these units. (The molar mass is the mass of a sample of the element divided by its amount of substance. This explains why the units are g/mol.) Alternatively, you can also say the number is ...


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Atomic mass is not exactly proportional to the mass number of the nucleus. Let's look at all the complicated factors that appear in one little atomic mass value: Particles: Protons and neutrons do not have exactly the same mass Binding Energy: The mass of a nucleus is less than the sum of the individual protons and neutrons because energy is lost (so mass ...


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I'm not sure of any conventional ways of electroplating selenium, but you could use a technique such as magnetron sputtering to spray a thin film of selenium onto another metal. Heck, you could even use glass or wood if you wanted to do it that way. And if you're going for thin, this technique can get you some of the thinnest, smoothest layers of metal out ...


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One of the largest issues as to your question is Plutonium 244, or Pu-244. Its half-life is just over 80 million years, which (given the existence of thorium and uranium with much higher half lives) suggests that it like those other high-proton elements must have been originally been produced in supernovae and debated since then. Unlike the decay ...


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