Notes

Ideal gas molecules do not attract or repel each other. The only interaction between ideal gas molecules would be an elastic collision upon impact with each other or an elastic collision with the walls of the container.

elastic collision refers to a collision wherein no kinetic energy is converted to other forms of energy during the collision. In other words, kinetic energy can be exchanged between the colliding objects (e.g. molecules), but the total kinetic energy before the collision is equal to the total kinetic energy after the collision.

Ideal gas molecules themselves take up no volume. The gas takes up volume since the molecules expand into a large region of space, but the Ideal gas molecules are approximated as point particles that have no volume in and of themselves.

d: A third factor in the mechanism of conduction is the thickness d of the material through which heat transfers. The figure above shows a slab of material with different temperatures on either side. Suppose that T2 is greater than T1, start subscript, 1, end subscript, so that heat is transferred from left to right. Heat transfer from the left side to the right side is accomplished by a series of molecular collisions. The thicker the material, the more time it takes to transfer the same amount of heat. This model explains why thick clothing is warmer than thin clothing in winters, and why Arctic mammals protect themselves with thick blubber.

delta T: The heat flow is proportional to the temperature difference

A: Owing to the fact that the number of collisions increases with increasing area, heat conduction depends on the cross-sectional area AAA. If you touch a cold wall with your palm, your hand cools faster than if you just touch it with your fingertip.