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 molecule): 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) rotational motion.
2) 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 faster.

All atoms can move from one point in space to another, and this kind of motion is known as translational motion. Additionally, molecules made 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 lattice.

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 and cook.

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 motion.

Sprinkle some pepper on a glass of water and watch it move. Then add a bit of soap.