Keeping Students Engaged

I was in my dyad today watching a class in science. Prior to today, I had only seen this class in reading. I was particularly interested in watching to see if they were engaged or not. The class was learning about solutions and mixtures and how to separate them. It was an inquiry based lesson. Overall, I noticed that as a whole this class was involved on a level that I had not seen before. Usually they are very quiet and reserved during reading.
However, I did notice a few students who were not completely engaged. One student who does not "like" his group would not participate at all. If he had been with friends, he would have goofed around but would he have learned more than being without his friends? I also noticed in this same group another student who wanted to participate but was "shut down" numerous times by two other students. This particular student is younger than everyone else in the class and the class as a whole shuns him. It appears that the class is annoyed by this particular student's immature actions. He is also from another country and has a very thick accent which makes him hard to understand. How could he be made valuable to the class? I then watched a third student, who had been engaged in the hands-on portion of the activity, shut down and stare blankly at the wall when it was time to read a related science article. How can teachers make it so students want to read these articles? The teacher has tried numerous avenues to try and work through the challenges associated with these three particular situations, but so far no success.
It was an interesting moment for me to realize that sometimes no matter what you try, students are not going to be interested. The talent that I, as a teacher, may see in individuals, who are so young and who do not realize their potential or how important learning is to life, will be a point of frustration. Those feelings along with the notion that just because I feel it is important, is it truly? Success, I am learning, is measured in many different ways. Each of us has their own notion of what it means to "make it." For some reason this all resonated strongly within me today during this class period and I wanted to share. Thanks for reading.