Ask A Scientist Chemistry Archive

Question:
How do scientists discover atoms can be split if they can't be seen?
 j middle school
 
Answer 1:
Actually, they can be seen.  Sophisticated instruments are able to detect
the fragments and pieces that are produced in an atom-splitting experiment.
Physicists may know a little more about the specifics here.  The pieces
may not be able to be seen, per se, but they will have energy and even
electrical charge that can be detected.
-Joe Schultz

Answer 2:  Very true...but there is even better evidence than that
from a series of new techniques that are used to sense corrugations
in a surface of atomic dimensions...one technique, called
scanning tunneling microscopy (STM) has been used to take "pictures"
of individual benzene molecules resting on a metal surface.
There are other "direct" imaging techniques as well, like
atomic force microscopy (ATM). Then there are tons of other methods
which "indirectly" tell us how atoms are connected up and how
they are arranged in crystals, such as X-ray crystallography
(atoms scatter x-rays and set up a diffraction pattern),
nuclear magnetic resonance (NMR) spectroscopy (protons "sing"
at different frequencies when put in a magnetic field and
the frequency depends on what other kinds of atoms are nearby
and how far apart they are)....plus tons more.
 
The evidence for the existence of atoms is OVERWHELMING.
Good question!
 
-topper