At room temperature and pressure, kinetic energy of the particles are minimum in case of:

Question

Question

This question was previously asked in

SSC GD Constable 2025 Official Paper (Held On: 05 Feb, 2025 Shift 1)

Answer 1

The correct answer is iron.

Key Points

At room temperature and pressure, the particles in solids like iron have the least kinetic energy compared to liquids or gases.
In solids, particles are tightly packed in a fixed lattice structure, which restricts their movement, minimizing their kinetic energy.
Iron, being a solid, exhibits strong intermolecular forces, which further limits the motion of its particles.
In contrast, gases like methane and liquids like water or kerosene have particles with higher kinetic energy due to weaker intermolecular forces and greater freedom of movement.
The kinetic energy of particles is directly proportional to their motion, and in the case of solids, this motion is minimal (restricted to vibrations about a fixed position).

Additional Information

Kinetic Energy in States of Matter
- Kinetic energy refers to the energy of motion. The particles in solids have the least kinetic energy, while gases have the highest.
- In liquids, particles have more kinetic energy than solids but less than gases, allowing them to flow but not expand indefinitely.
Intermolecular Forces
- Solids like iron have the strongest intermolecular forces, keeping particles in fixed positions.
- Liquids and gases have weaker intermolecular forces, which result in greater freedom of movement for their particles.
Particle Movement in Solids
- In solids, particles vibrate around fixed points but do not move freely, resulting in low kinetic energy.
- This is why solids maintain a definite shape and volume, unlike liquids and gases.
Temperature and Kinetic Energy
- Kinetic energy increases with temperature as particles gain more thermal energy.
- At room temperature, solids like iron remain in their low-energy state due to their rigid structure.