What is the force that makes atoms/molecules collect into
solid matter? What force brings all the atoms/molecules together to make
up a persons eye, say?
The force that HOLDS atoms and molecules together is electromagnetic(mostly
electric, but magnetic does plays a part). The negatively charged electrons
and positively charged atomic nuclei interact through the electromagnetic
force to stick together. There is more to it than "Coulomb's Law".
Electromagnetic force on the scale of atoms is more complex than on the
scale of charged balls. To discuss all details requires quantum physics.
Still, it is the electromagnetic force. Some atoms hold together very
tightly, forming solids. Less tight electromagnetic bonds result in liquid
As for what BRINGS the atoms together, there are a variety of possibilities.
In a biological situation, it is very often the work of proteins. These are
biological "workhorses" that have individual tasks for which they are
created. It may be to place a certain atom in the wall of a cell. It may
be to bend one molecule into another shape, allowing it to become a
different molecule. Often digestion plays a role. You drink a glass of
milk. A calcium atom is digested. Proteins then place the atom in your
bone to heal a broken arm.
When you get to the level of outer space, the driving force is gravity. A
meteor is pulled to a planet by gravity. The meteor burns up passing
through the atmosphere. The atoms that were part of the meteor are now part
of the planet. There are many ways to bring atoms together, but they all
use electromagnetic force to stay together as molecules.
Dr. Ken Mellendorf
Illinois Central College
depending on the material, there are a few different
forces that hold molecules together. There's metallic
bonding, ionic, covelant, hydrolic, Van de Wall, etc.
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Update: June 2012