# Linked Questions

12 questions linked to/from Units of mass on the atomic scale
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### Are atomic mass unit (amu), unified mass unit (u) and Dalton (Da) the same unit but with different names? [duplicate]

I recently read up on some chemistry and found these units of mass: atomic mass unit (amu) unified atomic mass unit (u) Dalton (Da) Are they all the same unit but just with different names or are ...
1answer
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### Why is the atomic mass unit less than the mass of both a neutron and a proton? [duplicate]

The atomic mass unit is $1.6605 \times 10^{-27}$ kg. This is less than the mean of the masses of 6 protons and 6 neutrons. How do we account for the lower mass ? My understanding is that some of the ...
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### Atomic weight and its units [duplicate]

I am quite confused when it comes to this, there are quite a lot of definitions of the above terms in numerous books and websites. However the definitions do not match each other. So, here are the two ...
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### What is the difference between “molecular mass”, “average atomic mass” and “molar mass”?

I don't understand the difference between "molecular mass" and "average atomic mass". They seem like the same thing to me. Is it that average atomic mass is just the weighted average of the "weights"/...
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### Quick and simple explanation of molar mass, molecular mass and atomic mass

As a physics student, I hardly deal with such quantities and when I do, I blunder through. I think it’s a good time to be given a good explanation for these since I’m in a class of Nuclear physics. I ...
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### Mass number, (relative) atomic mass, average mass

What is the difference between mass number, atomic mass and average atomic mass? I know the mass number is the amount of protons + the amount of neutrons. The average mass is the weighed average of ...
2answers
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### When to use Da or u for mass units

Following up on the question Units of mass on the atomic scale, Daltons (Da) and unified mass units (u) are equivalent, but which is used seems to depend on context. For example, when discussing ...
1answer
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### why “amu” is used as a unit in relative atomic mass? [duplicate]

Unified atomic mass unit (amu) is defined as $1/12$ of the mass of a Carbon-12. I want to know is this amu equal to $\pu{1.99e-23 g}$ and why do we use amu which is $1/12$ the mass of carbon? Why use "...
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### Difference between atomic mass, mass number, atomic weight, and relative atomic mass [duplicate]

I think this question is common, but i want a little help. I'm little confused. What I concluded. Relative atomic mass/Atomic weight (both are exactly the same) - It is the mass of atom calculated as ...
1answer
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### Why the term 'unified' in “unified mass unit”? [closed]

Why different unit symbols - amu, u and dalton are used for representing atomic mass? And what does the term 'unified' mean in "unified mass unit"? Thank you.
1answer
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### The unit of relative atomic mass [closed]

The mass of Carbon-12 atom is 12.0000000 a.m.u. For relative isotopic mass, e.g. Mg-24 atom is 24 compare with the c-12 as standard. However, why is it unitless? Shouldn't it be 24 a.m.u.?
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### Can anyone give me detailed logical solution to my questions? [closed]

What is 1 amu? From where it is derived? Why it is compared with carbon-12? Why it was once compared with hydrogen-1? and now its not? Can anyone please explain me logically? And what would have ...