Chemistry Regents Practice Test

According to the kinetic molecular theory, how are the particles of an ideal gas characterized?

1. They are tightly packed together

2. They are bonded to each other

3. They are separated by great distances, compared to their size

4. They vibrate in fixed positions

The correct answer is: They are separated by great distances, compared to their size

According to the kinetic molecular theory, the particles of an ideal gas are characterized by being separated by great distances relative to their size. This theory posits that gas particles are in constant, random motion and that the volume occupied by the individual gas particles themselves is negligible compared to the total volume of the gas. In this model, the large distances between particles allow them to move freely without significant interactions, aside from occasional elastic collisions. This characteristic leads to the unique behaviors of gases, such as their ability to expand to fill a container and have low density compared to solids and liquids. The other characteristics mentioned in the other options do not align with the behavior of gas particles as described by the kinetic molecular theory. The particles are not tightly packed together or bonded, and they do not vibrate in fixed positions, which is a property more associated with solids. Instead, the ideal gas model illustrates the significant separation and independent motion of gas particles.