Ideal Gases: Intermolecular Forces & Kinetic Energy

[Misr]

http://pages.towson.edu/ladon/gases.html

2. Collisions between ideal Gases are "elastic". This means that no attractive or repulsive forces are involved during collisions. Also, the kinetic energy of the gas molecules remains constant since theses interparticle forces are lacking.

"Elastic" means that the energy of the particle before collision equals to the energy of the particle after collision.
How is this related to the presence or absence of intermolecular forces and

How is this related to kinetic energy?
Does the particles loses energy when it is attracted to another particle?if yes,then could you explain how?

 

[TaxOnFear]

"Elastic" means that the energy of the particle before collision equals to the energy of the particle after collision.

Think about it, if you have an attractive force, then the kinetic energy will be greater before the collision than after, therefore the energy before the collision ≠ the energy after the collision, likewise with a repulsive force.

Which also answers your second question.

 

[Misr]

Yes I know that and i already mentioned it in the first post but I can't just imagine why intermolecular forces makes molecules lose energy?
but I can imagine that when the molecule rebounces , the other molecule attracts it so decreasing its kinetic energy and its speed.Is that okay?
how about the repulsive forces?

 

[Misr]

hello there?what's wrong with my post