What is the state of matter in which particles are widely spaced and move freely with high kinetic energy?

Analysis

The question asks us to identify a state of matter based on three specific physical characteristics:

1. Particle spacing: The particles are "widely spaced."
2. Movement: The particles move "freely."
3. Energy: The particles possess "high kinetic energy."

Concept Explanation

To understand this, let's look at the kinetic theory of matter for the three common states:

• Solids: Particles are packed closely together in a fixed, orderly arrangement. They only vibrate about fixed positions and have the lowest kinetic energy.
• Liquids: Particles are close together but can slide past one another. They have more kinetic energy than solids but are still restricted by intermolecular forces.
• Gases: Particles are far apart (widely spaced) with very weak intermolecular forces. They move randomly and rapidly in all directions, meaning they possess high kinetic energy.
• Plasma: While plasma is a state of matter consisting of ionized gas, in the context of standard JAMB Chemistry questions, the description of "widely spaced particles moving freely" is the classic definition of the Gaseous state.

Step-by-Step Solution

1. Evaluate Option B (Solid): Incorrect. Particles are tightly packed and vibrate in fixed positions, not moving freely.
2. Evaluate Option A (Liquid): Incorrect. Particles are close together and have moderate kinetic energy, not widely spaced.
3. Evaluate Option D (Gas): Correct. In a gas, the intermolecular forces are negligible, allowing particles to be far apart and move at high speeds (high kinetic energy) in random directions.
4. Evaluate Option C (Plasma): While plasma involves high energy, it is an ionized state. In the context of basic chemistry curricula, the description provided is the standard definition for a gas.

Conclusion

The state of matter characterized by widely spaced particles and high kinetic energy is the gaseous state.

Exam Tip: Remember the "Kinetic Theory of Matter" mnemonic: Solid (Vibrate), Liquid (Slide), Gas (Fly). If the particles are "flying" around, they have high kinetic energy and are in the gaseous state.