If an Atom was the size of a grain of salt

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Discussion Overview

The discussion revolves around the conceptual scaling of atoms to the size of a grain of salt, exploring the implications of such a scale in terms of relative sizes of various objects, including Earth and other atomic structures. Participants engage in calculations and comparisons, touching on theoretical and conceptual aspects of atomic dimensions.

Discussion Character

  • Exploratory
  • Mathematical reasoning
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants propose that if a helium atom were scaled to the size of a grain of salt, it would result in a grain of salt being approximately 100 meters wide, while a caesium atom would lead to a grain of salt being around 16 meters wide.
  • Others discuss the size of atoms, noting that hydrogen is smaller than helium, and raise questions about the accuracy of atomic size comparisons.
  • A participant mentions a diameter ratio of about 50 million when comparing the size of an atom to that of a grain of salt, based on assumed measurements.
  • There is a request for clarification on what object would represent the size of a grain of salt at this scale, indicating a lack of consensus on specific examples.
  • Some participants express uncertainty regarding the size of the transistor mentioned in a linked article and seek to relate it to the size of a grain of salt.
  • One participant challenges another's understanding of atomic sizes, suggesting a need for verification of claims made about atomic dimensions.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the specific object that would represent the size of a grain of salt at the atomic scale, and there are multiple competing views regarding the calculations and implications of atomic sizes.

Contextual Notes

Some calculations depend on assumptions about the sizes of atoms and grains of salt, and there are unresolved questions regarding the variability of atomic sizes based on bonding and other factors.

Embison
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What object would represent the size of a grain of salt at this scale?

Would it be bigger than Earth?
 
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Embison said:
What object would represent the size of a grain of salt at this scale?

Would it be bigger than Earth?
Is this a homework problem?

What are your thoughts on your problem?
 
The smallest atom is helium at ~30pm, a very large atom like caesium is ~225pm. Salt obviously varies in size but let's say it's particularly fine at 100μm then a helium atom is ~3 millionth of the size and a caesium atom is ~0.5 millionth of the size. So if a helium atom was as large as a grain of salt a grain of salt would be ~100m wide and for a caesium atom it would be ~16m wide.

I'm pretty sure my math is correct there :wink:
 
No. I'm reading this...

http://nextbigfuture.com/2012/02/single-atom-transistor-is-perfect.html?m=1

and I'm curious about how small that really is.
 
Last edited by a moderator:
If I remember correctly, an atom is roughly in the 10^-11 - 10^-10 scale, and an average grain of salt could have a diameter of, let's say, 10^-3 m (assuming it's a sphere).

This leaves you with a diameter ratio of about 50 million.
 
So what object would represent the size of the grain of salt?
 
Embison said:
So what object would represent the size of the grain of salt?
See my post #3 above.
 
I did but you didnt mention any objects.
 
Embison said:
I did but you didnt mention any objects.
16 metres long is roughly five cars. 100 metres long is roughly the width of the international space station. That's obviously just length so use your imagination to make it 3d.
 
  • #10
Ryan_m_b said:
The smallest atom is helium at ~30pm
A hydrogen would be a bit smaller, being a single proton.
 
  • #11
Thanks Ryan. I wasnt sure if you meant miles or meters.

Is it possible to estimate which atomic scale that transistor was manufactured at from the link I posted? And what size would a grain of salt represent from my original question compared to the size of that transistor?

Thank you for any help!
 
  • #13
Embison said:
Thanks Ryan. I wasnt sure if you meant miles or meters.

Is it possible to estimate which atomic scale that transistor was manufactured at from the link I posted? And what size would a grain of salt represent from my original question compared to the size of that transistor?

Thank you for any help!
Well the atom they mention is phosphorous which is roughly 180pm in size (note that atom "size" can vary based on how they bond IIRC).

Taking a grain of salt to be 100μm in size: 100000000pm/180pm = 555555.55
100μm*555555.55 = 55555555μm = 55555.555mm = 55.555555m

So a grain of salt would be ~half the size of a 100m sprint track.
 

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