I deal with each challenging student in a different way because no two students are exactly the same. If they are the angry student, I usually pull them off to the side to get to the root of their anger and if it is out of my ability to help them, I send them to our school counselors to get them the help they need. Alot of times they just need to vent their frustrations and they become a totally different person in class because you took the time to listen to them. If they are inattentive or talking in the back, I call on them and ask questions to keep them engaged because they never know when a question could possibly come their way. I find the silent students to be the most difficult to deal with because their silence makes it hard to see if the information you are giving "sinks in" or not. I have found that after I have finished a lecture, I hand out what I call "The One Minute Survey". I have every student fill out a very short survey that asks them what they understood well and what part of said lecture they did not quite get. It is an anonymous survey so no names are necessary. From that survey I can get some input from the "quiet" students as they don't have that feeling of having "all eyes on them" if they were to raise their hand during class that they may find intimidating.