Why can scientists ignore the forces of attraction between particles in a gas under ordinary conditions?
They do not exist for particles that have kinetic energy.
They are too weak to have an effect at the temperatures at which most gases exist.
They are too weak to have an effect at great distances between gas particles.
All of the above statements are partially correct and contribute to why scientists can ignore the forces of attraction between particles in a gas under ordinary conditions.
Firstly, gases consist of particles, such as atoms or molecules, that constantly move in random directions with high kinetic energy. The kinetic energy of gas particles is much higher than the attractive forces between them. As a result, the particles are typically far apart from each other and have enough energy to overcome any attractive forces, enabling them to freely move and collide with one another.
Secondly, the forces of attraction between gas particles, such as van der Waals forces or London dispersion forces, arise from temporary fluctuations in electron distribution. These forces are relatively weak compared to other intermolecular forces like ionic or covalent bonds. At ordinary temperatures and pressures, the average kinetic energy of gas particles is high enough to overcome these weak forces. Hence, the forces of attraction become insignificant and can be ignored in most cases.
Lastly, the distance between gas particles in a typical gas sample is typically quite large compared to the size of the particles themselves. Since the attractive forces between gas particles rapidly decrease with distance, they become negligible over larger separations. Consequently, these relatively weak forces have minimal effects on the behavior and properties of gases under ordinary conditions.
However, it is important to note that under extreme conditions of low temperatures or high pressures, the forces of attraction between gas particles may become significant and cannot be ignored. Under such conditions, the behavior of gases may deviate from ideal gas laws, and scientists must consider the intermolecular forces in their analysis.