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is it atom or element that is shown on periodic table?

I know that an element is a group of atom of the same type, if so do they guage the average no. of protons, etc. to indicate on the periodic table? Or are they atoms whats shown on it??

Thanks
Original post by BrightBlueStar11
I know that an element is a group of atom of the same type, if so do they guage the average no. of protons, etc. to indicate on the periodic table? Or are they atoms whats shown on it??

Thanks

I’m not entirely sure what you’re asking but the periodic table shows the name of the element and some info about atoms of that element, E.g. H is the element hydrogen, which has a mass number of 1 and an atomic number of one. This means an atom of hydrogen has one proton and no neutrons. All atoms of an element have the same number of protons, so hydrogen atoms always have 1 proton and helium atoms always have 2 protons etc. An atom with 20 protons is always a Calcium atom. It does get a bit more complicated with isotopes/mass numbers but hopefully this answers your Q?
Original post by BrightBlueStar11
I know that an element is a group of atom of the same type, if so do they guage the average no. of protons, etc. to indicate on the periodic table? Or are they atoms whats shown on it??

Thanks


The periodic table of the elements is a systematic means of arranging all the known elements.

As the elements can have different isotopes, the periodic table doesn’t really bother with all the different kinds of atom known to exist.

Check out the table of nuclides if you wanted to see a table with every known atom listed on it
Original post by TypicalNerd
The periodic table of the elements is a systematic means of arranging all the known elements.

As the elements can have different isotopes, the periodic table doesn’t really bother with all the different kinds of atom known to exist.

Check out the table of nuclides if you wanted to see a table with every known atom listed on it


are the atoms shown on the periodic table based on its most highest abundance? For example, if there are carbon-12 & carbon-13 and carbon-12 is most abundance, then is the one shown on the periodic table carbon-12?

Thanks :smile:
Original post by bea_murray0
I’m not entirely sure what you’re asking but the periodic table shows the name of the element and some info about atoms of that element, E.g. H is the element hydrogen, which has a mass number of 1 and an atomic number of one. This means an atom of hydrogen has one proton and no neutrons. All atoms of an element have the same number of protons, so hydrogen atoms always have 1 proton and helium atoms always have 2 protons etc. An atom with 20 protons is always a Calcium atom. It does get a bit more complicated with isotopes/mass numbers but hopefully this answers your Q?


Thanks :smile: Yes, it answers my question

Also, can I also ask if the atom shown on the periodic table based on its most highest abundance? For example, if there are carbon-12 & carbon-13 and carbon-12 is the most abundance, then is the one shown on the periodic table carbon-12?
Original post by BrightBlueStar11
Thanks :smile: Yes, it answers my question

Also, can I also ask if the atom shown on the periodic table based on its most highest abundance? For example, if there are carbon-12 & carbon-13 and carbon-12 is the most abundance, then is the one shown on the periodic table carbon-12?

Yes, that is true for most cases. However, depending on the periodic table you use (such as Edexcel's one for GCSE), for some elements such as chlorine and copper you may see fractional atomic masses, (35.5 and 63.5 respectively). This is because there isn't one isotope that occurs the majority of the time. Chlorine has two stable isotopes chlorine-35 and chlorine-37 with chlorine-35 accounting for roughly 3 out of every 4 naturally occurring chlorine atoms.
Original post by BrightBlueStar11
are the atoms shown on the periodic table based on its most highest abundance? For example, if there are carbon-12 & carbon-13 and carbon-12 is most abundance, then is the one shown on the periodic table carbon-12?

Thanks :smile:


No. They typically give the weighted mean mass of all the naturally occurring isotopes (sometimes rounded to the nearest integer).

One example is Copper, which often has it’s relative atomic mass quoted as 64 g mol^-1, even though Cu-64 doesn’t occur in nature.
(edited 1 year ago)
Original post by BrightBlueStar11
Thanks :smile: Yes, it answers my question

Also, can I also ask if the atom shown on the periodic table based on its most highest abundance? For example, if there are carbon-12 & carbon-13 and carbon-12 is the most abundance, then is the one shown on the periodic table carbon-12?


There's a 3 way choice

1. don't show the mass at all
2. show the mass of the most abundant isotope only - mass is shown as an integer (whole number)*
3. show the 'average' mass based on the natural abundance of the isotopes - mass is a decimal number
you can find examples of all these types

the third type would (probably) show the mass of H as 1.008 and the mass of C as 12.01

course natural abundance is actually a bit of a tricky idea - the relative abundance of carbon isotopes is going to be different in a lump of coal to a weetabix because C14 is unstable

*If there's no stable isotope as is the case with the very heaviest elements pick the one with the longest half life
The periodic table consists of elements ie. Gold, oxygen, carbon. The smaller number on these elements are the number of protons in an atom of that element. The bigger number is the number of protons and neutrons in an atom of that element.
Original post by BrightBlueStar11
Thanks :smile: Yes, it answers my question

Also, can I also ask if the atom shown on the periodic table based on its most highest abundance? For example, if there are carbon-12 & carbon-13 and carbon-12 is the most abundance, then is the one shown on the periodic table carbon-12?

@MouldyVinegar pretty much explained it but yes, on a simplified periodic table (E.go the one you use at GCSE level IIRC) you will probably get a whole number (i.e. 12 for C) which refers to the most abundant isotope (for all intents and purposes). And as @TypicalNerd says, the mass number on a periodic table will probably really be the weighted mean mass of all the isotopes of an element (that is, weighted by abundance), which may be rounded in a simplified periodic table, or may be left to a couple of decimal places (but you will probably only come across this at A level or further). For example, if the mass number for carbon on a periodic table is 12, this might just be the rounded weighted mean mass, but also tells us the C-12 is the most abundant isotope. If we say 90% of the carbon on earth is in the form of C-12, and the other 10% is C-13, we end up with a relative atomic mass (weighted mean mass) of 12.1, rounded to 12. Because the actual relative atomic mass rounds to 12 rather than 13, we know that there is more C-12 than C-13. I’m not sure if I’ve explained that very well but I hope that makes sense!
Original post by JamesBlue1234567
I know that an element is a group of atom of the same type, if so do they guage the average no. of protons, etc. to indicate on the periodic table? Or are they atoms whats shown on it??

Thanks


Thank you so much for that
Original post by bea_murray0
@MouldyVinegar pretty much explained it but yes, on a simplified periodic table (E.go the one you use at GCSE level IIRC) you will probably get a whole number (i.e. 12 for C) which refers to the most abundant isotope (for all intents and purposes). And as @TypicalNerd says, the mass number on a periodic table will probably really be the weighted mean mass of all the isotopes of an element (that is, weighted by abundance), which may be rounded in a simplified periodic table, or may be left to a couple of decimal places (but you will probably only come across this at A level or further). For example, if the mass number for carbon on a periodic table is 12, this might just be the rounded weighted mean mass, but also tells us the C-12 is the most abundant isotope. If we say 90% of the carbon on earth is in the form of C-12, and the other 10% is C-13, we end up with a relative atomic mass (weighted mean mass) of 12.1, rounded to 12. Because the actual relative atomic mass rounds to 12 rather than 13, we know that there is more C-12 than C-13. I’m not sure if I’ve explained that very well but I hope that makes sense!


You have really help me thank you

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