Hey guys, hope you can help me out a bit... this is pretty much kind of a basic question

, I guess I just need some direction about what to read up about before I understand this.

Here goes....

In general, bonds between atoms form when orbitals overlap right? Or is that not right?

For example, in this kind of reaction:

A+B -> C

when you add energy to this reaction (by heating it up for example), the reaction may go faster because the atoms move more and collide more. More collisions means that the probability of orbitals overlapping increase so then the probability of bond formation increases too... right?

But then, what about this...

Let's say I have 100 atoms in a box. These atoms can form bonds (sigma bonds, e.g.) with each other.

In the beginning, I put my box in the fridge, so all the atoms are cold and move kind of slowly, so they don't collide that much with each other.

Then one day I take the box out and put it on my stove and heat it up.

Now the box heats up and the atoms heat up and they have more energy and collide more.

I think if I put the stove at Gas mark 4 (the highest), then the probability that bonds are going to form will increase because the atoms will collide more than if I put the stove at Gas mark 2.

But now I don't know how to quantify this. How do I tell someone else that the probability of (e.g.) 1 bond forming between 2 atoms from 100 atoms in the box is X% at Gas mark 4 and (X-Y)% at Gas mark 2?

Cos obviously when I'm calculating the probability of a bond forming, I will need to take into account the velocity of the moving atoms in the box. I will also need to take into account that even when 2 atoms collide that won't necessarily form a bond because the orbitals might not overlap (e.g. if the atoms have some sp orbitals... I guess if they have isotropic orbitals that might be easier...).

Hope you can point me in some direction. I feel kind of lost now (and also stupid =_= cos I guess I should have already learnt this in high school....)

Thanks!