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# Why is everything on the periodic table 1 mole?

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1. my teacher was like everything on the periodic table is one mole

I know that 1mol=6.02x10^23 atoms/molecules/whatever

but why is everything on the periodic table 1 mole. and why is it compared carbon-12

the thing im really confused me is: if 1 ATOM of an element is 1 mole, does it mean that there are 6.03x10^23 something making up that 1 ATOM of that element.

I also know some atoms are made of isotopes, but some arent
2. One mol of a compound is the atomic mass in grams.
3. 1 atom is not one mole.

1 mole is the same as 6.02x1023 atoms of the same element.

The periodic table is based on the relative atomic mass and ordered by the atomic number.

I think it's based on carbon-12 because it was set as a standard years ago (I don't know exactly why but I couldn't care less about the history of things like these lol). So one mole of carbon equals 12.000g, whereas a mole of hydrogen is 1.008g, not 1.000. So carbon is used as it's molar mass is closest to it's mass number in grams.

Moles = Mass / molecular mass btw
4. (Original post by Kvothe the Arcane)
One mol of a compound is the atomic mass in grams.
so the atomic mass of any element say: sodium with mass of 22.990 is 1 mole and so is every other element.

also, am i correct in saying an element is a collection of 1 type of atom, collection as in lots of that 1 atom to make the element
5. (Original post by Frank Peters)
so the atomic mass of any element say: sodium with mass of 22.990 is 1 mole and so is every other element.

also, am i correct in saying an element is a collection of 1 type of atom, collection as in lots of that 1 atom to make the element
Spot on
6. (Original post by LogicIsKey)
Spot on
so is it correct in saying that all the atoms in the periodic table have a set amout of atoms that is used to make up the elements relative atomic mass

e.g. (this is just example, not really) imagine if all the atoms on the periodic table have 5+ atoms that make its element. So you would have a set number of 4 atoms to make the element. Therefore meaning the relative atomic mass is a set number of atoms that make up that element
7. (Original post by Frank Peters)
so is it correct in saying that all the atoms in the periodic table have a set amout of atoms that is used to make up the elements relative atomic mass

e.g. (this is just example, not really) imagine if all the atoms on the periodic table have 5+ atoms that make its element. So you would have a set number of 4 atoms to make the element. Therefore meaning the relative atomic mass is a set number of atoms that make up that element
You've got everything completely backwards.

You need only one nucleus to say you have an element. You need 6.02*1023 atoms to say you have one mole of an element.

The relative atomic masses in grams being one mole of the element is a consequence of how we define the mole, nothing more.

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