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# Why is the relative atomic mass of Chlorine is 35.5 Watch

1. Yeah, I don't get why.

I've tried searching but I need help.
2. The average mass is 35.5, about half of chlorine atoms have a RAM of 35, the other half 36, same with every other decimal one.
3. Thank the lord
Thank the lord
ooPS I DIDN'T FNISH THE POST
5. Oh god my reply is a trainwreck
6. What i meant to say was thank the lord my revision could help me qith this question. Basically the value is an average o all the isotopes taking into account the relative abundance
7. Thanks!

Good luck to all tomorrow
8. If a element has more than one isotope the relative atomic mass takes account of the relative abundance and RAM mass of each isotope, for chlorine (I think) about 3/4 is Cl-35 and about 1/4 is Cl-37, giving 35.5 overall, though I very much doubt this is necessary to know. The values will be different for each atom obviously, but that is the general idea.
9. (Original post by Jammy Duel)
The average mass is 35.5, about half of chlorine atoms have a RAM of 35, the other half 36, same with every other decimal one.
That's incorrect mate :/
There are two isotopes of Chlorine. Cl-35 and Cl-37. On average 75% of the atoms are Cl-35 and 25% are Cl-37. Therefore on average the atomic number is 35.5.
35+35+35+37 = 142
142 / 4 = 35.5
10. (Original post by Jono-Wolf)
That's incorrect mate :/
There are two isotopes of Chlorine. Cl-35 and Cl-37. On average 75% of the atoms are Cl-35 and 25% are Cl-37. Therefore on average the atomic number is 35.5.
35+35+35+37 = 142
142 / 4 = 35.5
It's been a while (5 to be precise) but the general point is correct

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11. That is the average weighted mass of an atom of chlorine compared to 1/12th the mass of an atom of carbon-12
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