Why the term 'unified' in “unified mass unit”?Units of mass on the atomic scaleWhy is it written as...
How is the idea of "X comes a distant third" commonly expressed in Russian?
What's the point of this scene involving Flash Thompson at the airport?
Is killing off one of my queer characters homophobic?
Modeling, view and projection transformation using vector and point in homogenous form
If the derivative of a function is square of it then it is constant
How to repair a laptop's screen hinges?
How do Windows version numbers work?
What does "Fotze" really mean?
Can you negate disadvantage on throwing a net by using the Lunging Attack maneuver of the Battle Master fighter?
Find values of x so that the matrix is invertible
Cubic programming and beyond?
What is a printer console?
Professor falsely accusing me of cheating in a class he does not teach, two months after end of the class. What precautions should I take?
In which ways do anagamis still experience ignorance?
Why did the Japanese attack the Aleutians at the same time as Midway?
How to check the quality of an audio sample?
Are there any double stars that I can actually see orbit each other?
wavelength of seismic wave with a gaussian source
How does one stock fund's charge of 1% more in operating expenses than another fund lower expected returns by 10%?
Is `curl {something} | sudo bash -` a reasonably safe installation method?
Help with understanding nuances of extremely popular Kyoto-ben (?) tweet
Would letting a multiclass character rebuild their character to be single-classed be game-breaking?
Filtering fine silt/mud from water (not necessarily bacteria etc.)
Why limit to revolvers?
Why the term 'unified' in “unified mass unit”?
Units of mass on the atomic scaleWhy is it written as “joule” and “J”?Atomic Mass of ¹²C before 1961Units of mass on the atomic scaleHow to retrieve Dalton value from m/z value?When to use Da or u for mass unitsWhat would be the unit for the calculation of the rate of reaction?How isotopes atomic mass was defined?How are the molar mass and molecular mass of any compound numerically the same?Types of concentration unitsBohr's model of an atom
.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty{ margin-bottom:0;
}
$begingroup$
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.
units atomic-structure
edited 5 hours ago
Loong♦
36.1k8 gold badges91 silver badges193 bronze badges
asked 8 hours ago
Pradhuman SharmaPradhuman Sharma
261 bronze badge
New contributor
Pradhuman Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
add a comment |
$begingroup$
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.
units atomic-structure
edited 5 hours ago
Loong♦
36.1k8 gold badges91 silver badges193 bronze badges
asked 8 hours ago
Pradhuman SharmaPradhuman Sharma
261 bronze badge
New contributor
Pradhuman Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
6
$begingroup$
This site typically gives answers that can be given in a paragraph or two. the history of units standardization is long and involves arbitrary changes. read the Wikipedia article en.wikipedia.org/wiki/Atomic_mass_unit.
$endgroup$
– MaxW
7 hours ago
1
$begingroup$
Related: Units of mass on the atomic scale
$endgroup$
– Loong♦
5 hours ago
add a comment |
$begingroup$
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.
units atomic-structure
edited 5 hours ago
Loong♦
36.1k8 gold badges91 silver badges193 bronze badges
asked 8 hours ago
Pradhuman SharmaPradhuman Sharma
261 bronze badge
New contributor
Pradhuman Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
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.
units atomic-structure
units atomic-structure
edited 5 hours ago
Loong♦
36.1k8 gold badges91 silver badges193 bronze badges
asked 8 hours ago
Pradhuman SharmaPradhuman Sharma
261 bronze badge
New contributor
Pradhuman Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 5 hours ago
Loong♦
36.1k8 gold badges91 silver badges193 bronze badges
asked 8 hours ago
Pradhuman SharmaPradhuman Sharma
261 bronze badge
New contributor
Pradhuman Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 5 hours ago
Loong♦
36.1k8 gold badges91 silver badges193 bronze badges
edited 5 hours ago
Loong♦
36.1k8 gold badges91 silver badges193 bronze badges
edited 5 hours ago
Loong♦
36.1k8 gold badges91 silver badges193 bronze badges
36.1k8 gold badges91 silver badges193 bronze badges
asked 8 hours ago
Pradhuman SharmaPradhuman Sharma
261 bronze badge
New contributor
Pradhuman Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 8 hours ago
Pradhuman SharmaPradhuman Sharma
261 bronze badge
asked 8 hours ago
Pradhuman SharmaPradhuman Sharma
261 bronze badge
261 bronze badge
New contributor
Pradhuman Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Pradhuman Sharma is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
6
$begingroup$
This site typically gives answers that can be given in a paragraph or two. the history of units standardization is long and involves arbitrary changes. read the Wikipedia article en.wikipedia.org/wiki/Atomic_mass_unit.
$endgroup$
– MaxW
7 hours ago
1
$begingroup$
Related: Units of mass on the atomic scale
$endgroup$
– Loong♦
5 hours ago
add a comment |
6
$begingroup$
This site typically gives answers that can be given in a paragraph or two. the history of units standardization is long and involves arbitrary changes. read the Wikipedia article en.wikipedia.org/wiki/Atomic_mass_unit.
$endgroup$
– MaxW
7 hours ago
1
$begingroup$
Related: Units of mass on the atomic scale
$endgroup$
– Loong♦
5 hours ago
6
6
$begingroup$
This site typically gives answers that can be given in a paragraph or two. the history of units standardization is long and involves arbitrary changes. read the Wikipedia article en.wikipedia.org/wiki/Atomic_mass_unit.
$endgroup$
– MaxW
7 hours ago
$begingroup$
This site typically gives answers that can be given in a paragraph or two. the history of units standardization is long and involves arbitrary changes. read the Wikipedia article en.wikipedia.org/wiki/Atomic_mass_unit.
$endgroup$
– MaxW
7 hours ago
1
1
$begingroup$
Related: Units of mass on the atomic scale
$endgroup$
– Loong♦
5 hours ago
$begingroup$
Related: Units of mass on the atomic scale
$endgroup$
– Loong♦
5 hours ago
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
Your question is historically important. Nobody has the energy to write an answer which would require several pages of an article. In short, it is a can of worms. For almost 5-6 decades chemists and physicists used a different scale for the atomic masses, so the atomic masses in the publications/books used by physicists did not exactly match what the chemists used for their own publications. Note that it is just not a matter of academic egos, the entire chemical industry is dependent on atomic weights (for calculations and trade). Money matters. This is why both the governments and the scientific community wanted to sort this out.
Both parties were not willing to budge because that would have affected their millions of pages of research. However a compromise was reached to use a common scale by two three sensible men i.e., they proposed to choose C-12 in the 1960s instead of oxygen. This process sort of "unified" the community of physicists and chemists and it did not affect the values of either party by much.
More history is given here, The AME2003 atomic mass evaluation (I). Evaluation of input data, adjustment procedures, Nuclear Physics A 729 (2003) 129–336
There are scores of other articles from the 1960-70s on the choice of C-12. Use Google Scholar. The original work is in French I guess, I did not check
T.P. Kohman, J.H.E. Mattauch and A.H. Wapstra, J. de Chimie Physique 55 (1958)
393.
answered 7 hours ago
M. FarooqM. Farooq
4,5205 silver badges19 bronze badges
$endgroup$
1
$begingroup$
Actually C-12 isn't the gold standard anymore. In 2018 the kilogram and Avogadro's number were redefined as fundamental constants. So the number of moles of C-12 in 12 grams of C-12 is now an experimental value. It will be very close to 1, but not 1 exactly.
$endgroup$
– MaxW
4 hours ago
add a comment |
Your Answer
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "431"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Pradhuman Sharma is a new contributor. Be nice, and check out our Code of Conduct.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fchemistry.stackexchange.com%2fquestions%2f117995%2fwhy-the-term-unified-in-unified-mass-unit%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Your question is historically important. Nobody has the energy to write an answer which would require several pages of an article. In short, it is a can of worms. For almost 5-6 decades chemists and physicists used a different scale for the atomic masses, so the atomic masses in the publications/books used by physicists did not exactly match what the chemists used for their own publications. Note that it is just not a matter of academic egos, the entire chemical industry is dependent on atomic weights (for calculations and trade). Money matters. This is why both the governments and the scientific community wanted to sort this out.
Both parties were not willing to budge because that would have affected their millions of pages of research. However a compromise was reached to use a common scale by two three sensible men i.e., they proposed to choose C-12 in the 1960s instead of oxygen. This process sort of "unified" the community of physicists and chemists and it did not affect the values of either party by much.
More history is given here, The AME2003 atomic mass evaluation (I). Evaluation of input data, adjustment procedures, Nuclear Physics A 729 (2003) 129–336
There are scores of other articles from the 1960-70s on the choice of C-12. Use Google Scholar. The original work is in French I guess, I did not check
T.P. Kohman, J.H.E. Mattauch and A.H. Wapstra, J. de Chimie Physique 55 (1958)
393.
answered 7 hours ago
M. FarooqM. Farooq
4,5205 silver badges19 bronze badges
$endgroup$
1
$begingroup$
Actually C-12 isn't the gold standard anymore. In 2018 the kilogram and Avogadro's number were redefined as fundamental constants. So the number of moles of C-12 in 12 grams of C-12 is now an experimental value. It will be very close to 1, but not 1 exactly.
$endgroup$
– MaxW
4 hours ago
add a comment |
$begingroup$
Your question is historically important. Nobody has the energy to write an answer which would require several pages of an article. In short, it is a can of worms. For almost 5-6 decades chemists and physicists used a different scale for the atomic masses, so the atomic masses in the publications/books used by physicists did not exactly match what the chemists used for their own publications. Note that it is just not a matter of academic egos, the entire chemical industry is dependent on atomic weights (for calculations and trade). Money matters. This is why both the governments and the scientific community wanted to sort this out.
Both parties were not willing to budge because that would have affected their millions of pages of research. However a compromise was reached to use a common scale by two three sensible men i.e., they proposed to choose C-12 in the 1960s instead of oxygen. This process sort of "unified" the community of physicists and chemists and it did not affect the values of either party by much.
More history is given here, The AME2003 atomic mass evaluation (I). Evaluation of input data, adjustment procedures, Nuclear Physics A 729 (2003) 129–336
There are scores of other articles from the 1960-70s on the choice of C-12. Use Google Scholar. The original work is in French I guess, I did not check
T.P. Kohman, J.H.E. Mattauch and A.H. Wapstra, J. de Chimie Physique 55 (1958)
393.
answered 7 hours ago
M. FarooqM. Farooq
4,5205 silver badges19 bronze badges
$endgroup$
1
$begingroup$
Actually C-12 isn't the gold standard anymore. In 2018 the kilogram and Avogadro's number were redefined as fundamental constants. So the number of moles of C-12 in 12 grams of C-12 is now an experimental value. It will be very close to 1, but not 1 exactly.
$endgroup$
– MaxW
4 hours ago
add a comment |
$begingroup$
Your question is historically important. Nobody has the energy to write an answer which would require several pages of an article. In short, it is a can of worms. For almost 5-6 decades chemists and physicists used a different scale for the atomic masses, so the atomic masses in the publications/books used by physicists did not exactly match what the chemists used for their own publications. Note that it is just not a matter of academic egos, the entire chemical industry is dependent on atomic weights (for calculations and trade). Money matters. This is why both the governments and the scientific community wanted to sort this out.
Both parties were not willing to budge because that would have affected their millions of pages of research. However a compromise was reached to use a common scale by two three sensible men i.e., they proposed to choose C-12 in the 1960s instead of oxygen. This process sort of "unified" the community of physicists and chemists and it did not affect the values of either party by much.
More history is given here, The AME2003 atomic mass evaluation (I). Evaluation of input data, adjustment procedures, Nuclear Physics A 729 (2003) 129–336
There are scores of other articles from the 1960-70s on the choice of C-12. Use Google Scholar. The original work is in French I guess, I did not check
T.P. Kohman, J.H.E. Mattauch and A.H. Wapstra, J. de Chimie Physique 55 (1958)
393.
answered 7 hours ago
M. FarooqM. Farooq
4,5205 silver badges19 bronze badges
$endgroup$
Your question is historically important. Nobody has the energy to write an answer which would require several pages of an article. In short, it is a can of worms. For almost 5-6 decades chemists and physicists used a different scale for the atomic masses, so the atomic masses in the publications/books used by physicists did not exactly match what the chemists used for their own publications. Note that it is just not a matter of academic egos, the entire chemical industry is dependent on atomic weights (for calculations and trade). Money matters. This is why both the governments and the scientific community wanted to sort this out.
Both parties were not willing to budge because that would have affected their millions of pages of research. However a compromise was reached to use a common scale by two three sensible men i.e., they proposed to choose C-12 in the 1960s instead of oxygen. This process sort of "unified" the community of physicists and chemists and it did not affect the values of either party by much.
More history is given here, The AME2003 atomic mass evaluation (I). Evaluation of input data, adjustment procedures, Nuclear Physics A 729 (2003) 129–336
There are scores of other articles from the 1960-70s on the choice of C-12. Use Google Scholar. The original work is in French I guess, I did not check
T.P. Kohman, J.H.E. Mattauch and A.H. Wapstra, J. de Chimie Physique 55 (1958)
393.
answered 7 hours ago
M. FarooqM. Farooq
4,5205 silver badges19 bronze badges
answered 7 hours ago
M. FarooqM. Farooq
4,5205 silver badges19 bronze badges
answered 7 hours ago
M. FarooqM. Farooq
4,5205 silver badges19 bronze badges
answered 7 hours ago
M. FarooqM. Farooq
4,5205 silver badges19 bronze badges
4,5205 silver badges19 bronze badges
1
$begingroup$
Actually C-12 isn't the gold standard anymore. In 2018 the kilogram and Avogadro's number were redefined as fundamental constants. So the number of moles of C-12 in 12 grams of C-12 is now an experimental value. It will be very close to 1, but not 1 exactly.
$endgroup$
– MaxW
4 hours ago
add a comment |
1
$begingroup$
Actually C-12 isn't the gold standard anymore. In 2018 the kilogram and Avogadro's number were redefined as fundamental constants. So the number of moles of C-12 in 12 grams of C-12 is now an experimental value. It will be very close to 1, but not 1 exactly.
$endgroup$
– MaxW
4 hours ago
1
1
$begingroup$
Actually C-12 isn't the gold standard anymore. In 2018 the kilogram and Avogadro's number were redefined as fundamental constants. So the number of moles of C-12 in 12 grams of C-12 is now an experimental value. It will be very close to 1, but not 1 exactly.
$endgroup$
– MaxW
4 hours ago
$begingroup$
Actually C-12 isn't the gold standard anymore. In 2018 the kilogram and Avogadro's number were redefined as fundamental constants. So the number of moles of C-12 in 12 grams of C-12 is now an experimental value. It will be very close to 1, but not 1 exactly.
$endgroup$
– MaxW
4 hours ago
add a comment |
Pradhuman Sharma is a new contributor. Be nice, and check out our Code of Conduct.
Pradhuman Sharma is a new contributor. Be nice, and check out our Code of Conduct.
Pradhuman Sharma is a new contributor. Be nice, and check out our Code of Conduct.
Pradhuman Sharma is a new contributor. Be nice, and check out our Code of Conduct.
Thanks for contributing an answer to Chemistry Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fchemistry.stackexchange.com%2fquestions%2f117995%2fwhy-the-term-unified-in-unified-mass-unit%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
6
$begingroup$
This site typically gives answers that can be given in a paragraph or two. the history of units standardization is long and involves arbitrary changes. read the Wikipedia article en.wikipedia.org/wiki/Atomic_mass_unit.
$endgroup$
– MaxW
7 hours ago
1
$begingroup$
Related: Units of mass on the atomic scale
$endgroup$
– Loong♦
5 hours ago