Collision question without using Rigid body

Questions & Answers
1

Basically I have a list of particles

list1 not really sure how to start the body of the for any suggestions would help

         for(i=0; i < list1.Count; i++)
		{
		    for(int j =i+1; j < list1.Count; j++)
		    {
			  
      

		    }
	     }
2

The basic idea is correct for checking collisions between particles in the list. I would measure the distance between particle and particle[j]: if it’s smaller than some limit (the particle size, for instance), you have a collision - like this:
for(i=0; i < list1.Count-1; i++){
Vector3 posI = list1*.position; // get position of particle*
for(int j =i+1; j < list1.Count; j++){ // compare to the next ones:
if (Vector3.Distance(posI, list1[j].position) < minDist){
// collision between list1 and list1[j]
}
}
}
NOTE: list1 is assumed to be a list of Transform.