| In what ways do atoms or molecules move?|
|Question Date: 2018-11-09|
Atoms, molecules, and other types of particles can
move in space, i.e. move from one point to another
point. This kind of movement is called
translational movement, and can be measured
by the distance the particle travels. This type of
the movement is the same type of movement we
undergo when, for example, we walk from our house
to our school. Particles can also vibrate, or
"jiggle". For a molecule, vibrational motion
means that one or more atoms in it move relative
to the rest of the molecule. The following link
illustrates (each sphere is an atom in a
vibrational motion .
The last major type of motion particles undergo
is rotational motion. This happens when a
particle spins about an axis. These next two links
show the rotational motions of molecules: 1)
rotation animation .
Atoms can rotate, too, just like a basketball
can spin, or the Earth spins about its own axis.
Atoms make up molecules. Atoms are connected by
what we call chemical
bonds. Bonds are really just when atoms share
electrons, but we often think of
them as a spring that connects two atoms. There
are three main modes of
molecular movement - vibrational, translational,
and rotational. Vibrational
motion is when molecules sort of “wiggle” around
and the “springs” that connect atoms spring back
and forth. Translational movement is when
molecules move side to side. Rotational movement
is when sections of the molecule spin.
Generally speaking, molecules move more at higher
temperatures since heat is a type of energy.
All atoms and molecules (above absolute zero
Kelvin) are constantly moving. This is known as
the kinetic theory of matter. Hot atoms or
molecules move faster than cold atoms or
molecules. In a system of atoms, some will be
moving faster and some will be moving slower. The
system’s temperature is a measure of the average
kinetic energy of all the atoms in a system. As
the temperature increases, this means the average
kinetic energy of all the atoms is increasing;
therefore, on average, the atoms are moving
All atoms can move from one point in space
to another, and this kind of motion is known as
translational motion. Additionally,
up of more than one atom (through chemical bonds)
can vibrate, where the atoms wiggle about their
equilibrium position like a spring. Atoms that
make up a solid are also constantly vibrating
around their equilibrium position within the solid
Molecules can also rotate about a fixed
axis. It is worth noting that molecules can absorb
energy in the form of electromagnetic radiation
that they convert into kinetic energy (atomic
motion). For example, a microwave oven works by
zapping food with microwave (ca 2,450 megahertz)
radiation which causes water, fats, and sugars in
your food to vibrate. This increased molecular
motion of the atoms causes your food to heat up
Molecules themselves can move in any direction,
they can rotate, and they can vibrate as the atoms
within a molecule move back and forth relative to
each-other, as if the chemical bonds connecting
them were springs.
They bounce around and wiggle and jiggle around.
For molecules in water, that's called Brownian
Sprinkle some pepper on a glass of water and watch
it move. Then add a bit of soap.
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