Final answer:
In terms of the state of matter, gas is the phase in which the particles are most loosely packed. Gas particles are far apart from each other and move freely, unlike solid and liquid particles which are more tightly packed.
Step-by-step explanation:
The state of matter in which the constituent molecules are most loosely packed is known as a gas. In a gaseous state, the particles are far apart and move freely, which is why gas can easily expand and fill its container. Other states of matter like solids and liquids have particles more closely packed. For instance, in a solid state, particles are closely packed in a fixed position, while in a liquid state, they are close but can move past each other. However, in a gas, particles are far apart, moving freely and quickly, providing them with enough energy to overcome intermolecular forces.
Learn more about States of Matter