The Naked Scientists
  • Login
  • Register
  • Podcasts
      • The Naked Scientists
      • eLife
      • Naked Genetics
      • Naked Astronomy
      • In short
      • Naked Neuroscience
      • Ask! The Naked Scientists
      • Question of the Week
      • Archive
      • Video
      • SUBSCRIBE to our Podcasts
  • Articles
      • Science News
      • Features
      • Interviews
      • Answers to Science Questions
  • Get Naked
      • Donate
      • Do an Experiment
      • Science Forum
      • Ask a Question
  • About
      • Meet the team
      • Our Sponsors
      • Site Map
      • Contact us

User menu

  • Login
  • Register
  • Home
  • Help
  • Search
  • Tags
  • Recent Topics
  • Login
  • Register
  1. Naked Science Forum
  2. General Science
  3. General Science
  4. How do atomic models correlate with electron microscope observations?
« previous next »
  • Print
Pages: [1]   Go Down

How do atomic models correlate with electron microscope observations?

  • 3 Replies
  • 4884 Views
  • 5 Tags

0 Members and 1 Guest are viewing this topic.

Offline katieHaylor (OP)

  • Naked Scientist Producer
  • Global Moderator
  • Sr. Member
  • ********
  • 475
  • Activity:
    0%
  • Thanked: 2 times
  • Naked Science Forum Newbie
    • The Naked Scientists
How do atomic models correlate with electron microscope observations?
« on: 11/10/2017 11:55:31 »
David says:

When we look at pictures of atoms through an Electron Microscope, we see the atoms as ' blurry spheres ', as if there is a shell or covering over the atom itself. However, the model we present of atoms, as a diagram, is a nucleus with neutrons and the electrons and protons revolving around the nucleus. 

What sub-atomic particles make up this ' shell ' ?


What do you think?
Logged
 



Offline chiralSPO

  • Global Moderator
  • Naked Science Forum King!
  • ********
  • 3743
  • Activity:
    0%
  • Thanked: 531 times
Re: How do atomic models correlate with electron microscope observations?
« Reply #1 on: 11/10/2017 14:50:41 »
Protons and neutrons make up the nucleus. The "shell" is the electrons.

See the attached image which my colleague captured using TEM (transmission electron microscopy). This is about as high resolution as can be achieved using these types of techniques. As far as I understand the physics involved, electron microscopy cannot have the precision required to see the subatomic structure for essentially the same reasons that atoms are the size they are (both are determined by the quantum mechanical properties of electrons). However, the resolution is clear enough to see which parts of my sample are crystalline (where all the atoms are in neat rows) and where it is amorphous (random, but still with more order than the empty field on the right, which just looks kinda like static on an old tv). Note you can also see diffraction patterns appearing as halos around the edge of the particle being looked at.
* 14 lattice burned.jpg (228.33 kB . 668x692 - viewed 4063 times)
« Last Edit: 11/10/2017 22:26:22 by chiralSPO »
Logged
 
The following users thanked this post: jeffreyH

Offline syhprum

  • Naked Science Forum King!
  • ******
  • 5198
  • Activity:
    0%
  • Thanked: 74 times
Re: How do atomic models correlate with electron microscope observations?
« Reply #2 on: 11/10/2017 20:10:27 »
Noting the 2nM bar on the picture it is incredible to think that transistors can be built taking up only 14nM 
Logged
 

Offline evan_au

  • Global Moderator
  • Naked Science Forum GOD!
  • ********
  • 11035
  • Activity:
    9%
  • Thanked: 1486 times
Re: How do atomic models correlate with electron microscope observations?
« Reply #3 on: 11/10/2017 20:51:14 »
An even closer image using a scanning tunneling microscope with individual atoms is shown here:
https://en.wikipedia.org/wiki/IBM_(atoms)

Electron microscopes have been able to produce images down to about 50pm resolution, while a Xenon atom is about 300pm across. This means that the "blur" will be about 17% of the width of the atom. But to achieve these resolutions, they have to use very high accelerating voltages - up to 400,000 Volts (ie very high-energy/short wavelength electrons). This disturbs the sample being examined, punching several atoms deep into the material, and interacting with both electrons and the atomic nucleus (electrons approaching the nucleus produce X-Rays).

The scanning tunneling microscope is much gentler, using low voltages (eg up to 5V) to examine the surface; this does not disturb the surface so much. This senses the electron density in just the top atom on the surface.
Logged
 



  • Print
Pages: [1]   Go Up
« previous next »
Tags: atomic model  / electron microscopy  / electrons  / neutrons  / protons 
 
There was an error while thanking
Thanking...
  • SMF 2.0.15 | SMF © 2017, Simple Machines
    Privacy Policy
    SMFAds for Free Forums
  • Naked Science Forum ©

Page created in 0.27 seconds with 34 queries.

  • Podcasts
  • Articles
  • Get Naked
  • About
  • Contact us
  • Advertise
  • Privacy Policy
  • Subscribe to newsletter
  • We love feedback

Follow us

cambridge_logo_footer.png

©The Naked Scientists® 2000–2017 | The Naked Scientists® and Naked Science® are registered trademarks created by Dr Chris Smith. Information presented on this website is the opinion of the individual contributors and does not reflect the general views of the administrators, editors, moderators, sponsors, Cambridge University or the public at large.