The Structure of the Atom


Exploring the atom has led to many technological advances in medicine, explosives, geology, even things you use every day and take for granted, like electricity, cell phone, even your clothing!


Our exploration of the atom begins with a brief history of scientists and how they have modeled their understanding of the basic building block matter.


Subatomic particles

Our understanding of the atom was very limited in the time of the Greeks, when it was first proposed that matter was not infinitely divisible, but that the smallest piece of matter was the atom. Since that time, much has been learned about the nature of the atom and our understanding of the nature of matter and the atom has changed. Discoveries by Thomson (the electron), Rutherford (the proton), and Chadwick (the neutron) have changed how we model the nature of the atom. No longer is the atom viewed as being indivisible, but now as being composed of these particles smaller than an atom, known as subatomic particles. A representation of the atom is shown below.



learning activity Roll over the image to see descriptions of the subatomic particles found in the atom.
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Build an Atom
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An atom is so small that it cannot be seen with a microscope, so chemists and physicists developed an instrument known as a scanning tunnelling microscope to trace the outline of the atom. While you still can't see an atom, scientists have the ability to manipulate their location and visualize the shape of the electron movement around the nucleus.





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