Concept:Heat conduction depends on particle spacing and collision frequency.
Explanation:In solids, particles are closely packed and vibrate about fixed positions.
This allows kinetic energy to be transferred rapidly through particle collisions.
In liquids and gases, particles are farther apart and move more freely.
The larger spacing reduces the rate of collision between particles.
Therefore, the transfer of thermal energy by conduction is slower in liquids and gases.
Convection also plays a role in fluids, but pure conduction is less effective than in solids.
Thus, the efficiency of conduction in liquids and gases is lower than in solids.
Answer:A. less efficient than solid