# relative atomic mass confused...a level chem

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#1
this is the definition on my teachers ppt:
the relative atomic mass of an element is the average mass of its atoms, compared to 1/12th the relative atomic mass of a carbon-12 atom.

wth i dont understand how the relative atomic mass is relative to the relative mass of something else lol :/
0
10 months ago
#2
Lmaooooooo
0
10 months ago
#3
Sorry I had to laugh 😂😂😂
0
10 months ago
#4
0
10 months ago
#5
(Original post by vix.xvi)
this is the definition on my teachers ppt:
the relative atomic mass of an element is the average mass of its atoms, compared to 1/12th the relative atomic mass of a carbon-12 atom.

wth i dont understand how the relative atomic mass is relative to the relative mass of something else lol :/
aha I get the confusion too dw
Basically, the mass of an element is on a scale where 1 atom of carbon-12 (the isotope is the C-12 bit) is 12
1
10 months ago
#6
Just memorise the definition
0
#7
(Original post by elliemcg24)
aha I get the confusion too dw
Basically, the mass of an element is on a scale where 1 atom of carbon-12 (the isotope is the C-12 bit) is 12
ooh ok i sort of get it thanks

(Original post by CaptainDuckie)
Lmaooooooo
lol whats so funny

(Original post by Dexter345)
Just memorise the definition
but i want to understand it too
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10 months ago
#8
(Original post by vix.xvi)
lol whats so funny

Yeah, just memorise the definition tbh, there’s not much they’re going to test you on this
0
10 months ago
#9
(Original post by vix.xvi)
this is the definition on my teachers ppt:
the relative atomic mass of an element is the average mass of its atoms, compared to 1/12th the relative atomic mass of a carbon-12 atom.

wth i dont understand how the relative atomic mass is relative to the relative mass of something else lol :/
The atomic mass unit (aka Dalton, often written as 'u') is defined as 1/12th of the mass of a carbon nucleus. This is about 1.66*10-27 kg, slightly less than the mass of an individual proton or neutron thanks to nuclear binding energy. Atomic mass is defined relative to that specific mass.
1
#10
(Original post by Sinnoh)
The atomic mass unit (aka Dalton, often written as 'u') is defined as 1/12th of the mass of a carbon nucleus. This is about 1.66*10-27 kg, slightly less than the mass of an individual proton or neutron thanks to nuclear binding energy. Atomic mass is defined relative to that specific mass.
oohh

thank you!!
0
10 months ago
#11
(Original post by vix.xvi)
this is the definition on my teachers ppt:
the relative atomic mass of an element is the average mass of its atoms, compared to 1/12th the relative atomic mass of a carbon-12 atom.

wth i dont understand how the relative atomic mass is relative to the relative mass of something else lol :/
basically, because atoms are so small, you would want to compare it to something. like for example, if someone asked you for the size of an ant, you would rather say that it was 1000 times smaller than a mouse, rather than the actual size of the ant. The same applies to elements. because carbon 12 weighs exactly 12 grams, you can easily just say that for one unit of it, we can calculate the mass of the rest of the atoms relative to it. for example, oxygen weighs 16 grams, and carbon weighs exactly 12 grams, so that means if you take exactly 1 unit of that 12 grams of carbon, we could multiply it by 16 to get 16. but obviously, some atoms have isotopes and the mass would vary, but we still compare it to carbon 12.
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