Final answer:
Molecules have the most energy to vibrate in the gas phase, where they can move freely and are not bound by intermolecular forces. Liquids have more energy than solids but less than gases, enabling particles to slide past one another. Plasma is the most energetic state, achieved by heating a gas until ionization occurs.
Step-by-step explanation:
The state of matter in which molecules have more energy to vibrate is in the gas phase. Compared to a liquid, where atoms or molecules have more energy than in a solid but are still held together by mutual attraction and can slide past one another, in a gas, these particles have enough energy to move freely and are not bound by these attractive forces. In terms of energy levels, solids have the least amount of energy where the particles can only vibrate about a fixed position and do not move freely.
As energy increases, typically with the addition of heat, the particles in a solid can start to overcome the intermolecular forces holding them together, leading to a liquid state where they can slide over one another. When even more energy is added and these forces are broken completely, the material enters into a gas phase. Beyond these traditional states, there exists the plasma phase, which is the most energetic state of matter and is created by further heating a gas until particles are ionized.