Final answer:
The motion of molecules in a gas is random for individual molecules, but has a predictable overall distribution known as the Maxwell-Boltzmann distribution. The average kinetic energy depends only on temperature, not molecular type, which influences the speed of sound in a gas. Despite fast molecular speeds, the mean free path in air is small, resulting in no significant macroscopic air movement.
Step-by-step explanation:
Distribution of Molecular Speeds
The motion of molecules in a gas is random in magnitude and direction for individual molecules, but collectively they exhibit a predictable distribution of molecular speeds. This distribution is termed the Maxwell-Boltzmann distribution, which asserts that while some molecules move extremely fast, colliding billions of times per second, others may not move very far in a short period. Nonetheless, this rapid movement is responsible for the transmission of disturbances, such as sound waves, at rates correlated to molecular speeds.
The Maxwell-Boltzmann distribution has been confirmed through experimental analysis and is fundamental to our understanding of thermodynamics and kinetic theory. Notably, the average kinetic energy of molecules is solely dependent on the absolute temperature and not the type of molecule. This insight explains phenomena such as the speed of sound, which is approximately 340 m/s at room temperature and increases with temperature, being faster in gases with lighter molecular masses.
The mean free path represents the average distance a molecule traverses between collisions. Despite the high velocities, the mean free path in air is small, causing no significant macroscopic movement of air. However, this kinetic activity at the microscopic level has macroscopic implications, such as the propagation of sound waves.