The correct option is A.
Explanation
Matter is classified into three primary states—solid, liquid, and gas—based on the kinetic energy of particles and the strength of the intermolecular forces of attraction between them. These forces determine the proximity of particles and the resultant physical properties of the state.
- Gas: In the gaseous state, particles possess high kinetic energy and are far apart. The intermolecular forces of attraction are negligible or weakest, allowing particles to move freely in all directions.
- Liquid: In the liquid state, the forces of attraction are stronger than in gases but weaker than in solids. This allows particles to remain in contact while still being able to slide over one another, giving liquids a definite volume but no definite shape.
- Solid: In the solid state, the intermolecular forces of attraction are at their maximum. Particles are closely packed in fixed positions and can only vibrate about their mean positions, resulting in a definite shape and volume.
Therefore, the increasing order of the force of attraction is Gas < Liquid < Solid.
Key Takeaway:The strength of intermolecular forces is inversely proportional to the distance between particles; it is weakest in gases and strongest in solids.