I'm trying to develop a more intuitive understanding of the states of matter..specifically the difference between solid and liquid. To this end, I'd like to consider the most basic system in which the concept "state of matter" still applies. Obviously a system with a single atom doesn't qualify, as a state describes the relationship between atoms. So let's start with two.
Here's the setup...we have a system of two Mercury atoms traveling on a collision course in empty space. Let's consider three scenarios..
- Scenario 1: The two atoms travel at high speeds. Upon colliding, all of their kinetic energy is redirected outward, and they shoot off into space, never to meet again. We can say that they are in a "gaseous" state
- Scenario 2: The two atoms travel at moderate speeds. Upon colliding, their kinetic energy is redirected outwards but is not enough to overcome the attractive force between them and they stay near each other in some sort of binary orbit. We can say that they are in a "liquid" state.
- Scenario 3: The two atoms travel at low speeds. Upon colliding, they are immediately "stuck" to one another and we can say that they are in a "solid" state.
My questions are...
- What exactly is the difference between scenario 2 and 3 for these two atoms? Is it primary the distance between them?
- Do we need perhaps 3 or 4 atoms in order to notice a difference between solid and liquid states?
- Does this scenario really capture the most basic system in which the "state" would be descriptive?
- Am I thinking about this the right way?
A few additional notes...
- I recognize that states of matter are emergent and we don't typically discuss these properties in terms of a few particles.
- Since we are imagining just two molecules in a vacuum, we are not considering the effects of pressure, but rather just "temperature", or the speed they are traveling.
- I'm taking a classical view...treating the two atoms as billiard balls. Would quantum effects play an important role in this system?
Thanks in advance!