Dance, Dance, Dance

I hope that everyone enjoyed the little dance lesson offered in class today. Remember, when I D.J. the homecoming dance, I had better see all my students movin' and groovin'. Let's review the parts of the "Molecular Motion / States of Matter Dance" or if you prefer "States of Matter / Molecular Motion Dance".
Part 1 - "The Solid" - Fists together and an ever so slight motion showing the molecules vibrating. The fists cannot move around one another nor can they move apart from one another. This shows the "vibrational motion" that all solid molecules have when subjected to energy.

• Definition - Energy - the ability to cause change. Changing the position of a molecule due to movement requires energy.

Part 2 - "The Liquid" - Fists are still touching one another, but they can now move around each other in a circular motion. Vibrational motion is still retained and movement of the fists around each other illustrates the "rotational motion" now afforded to the molecules. Rotational motion is achieved because enough energy is absorbed by the material to cause the vibrational motion of the solid to become so intense, the bonds that once held the molecules in place as a solid are broken.

• Definition - Temperature - the direct measure of molecular motion. A substance's melting point (solid to a liquid; vibrational motion to rotational and vibrational motion) is the molecular motion rate (temperature) that causes the bonds between the solid particles (atoms, molecules) to be broken.

Part 3 - "The Gas" - Fists are no longer touching and are moving in all directions in three dimensional space. Vibrational and rotational motion are still retained and the movement of the fists in all directions illustrates the "translational motion" now afforded to the molecules. Translational motion is achieved because enough eneryg is absorbed by the material to cause the rotational motion of the liquid to become so intense, the bonds that once held the molecules together as a liquid (touching, but able to move around each other) are broken.

• Analogy - "The Mean Uncle" - You are at a family outing and you are a young child. You go to your uncle, "Please swing me!" Your uncle abliges you, but before he grabs your hands to swing you around in a circle, he puts grease all of you hands and arms and his hands and arms. As he spins you round and round and picks up more speed, the weak bond that exists between you and him (greasy hands) is broken quite easily. You end up flying off into a bush. This is just like a liquid. The molecular motion becomes so great (high enough temperature), the bonds holding the liquid molecules together are broken and a gas is formed.

Just as energy can be placed into a material to increase molecular motion and break bonds, thus changing states of matter, energy can be removed (or lost) from a material. As energy is removed, the molecular motion decreases. The decreased molecular motion does not allow the particles (atoms or molecules) to overcome the attractive forces between them, thus bonds are formed between the particles.

**Molecular motion exists as long as there is energy. What is the name of the theory when no energy exists, thus no molecular motion exists in matter.

***Absolute Zero is the theoretical point when all energy has been removed from matter and no molecular motion exists for atoms of an element.