It's my first year teaching, and my first experience with teaching middle school. I have four 6th grade classes which are going very well, and one 7th grade class that I'm struggling with a bit. On Thursday, they pretty much all left when the bell rang after I told them to wait at their tables until they're dismissed. So on Friday, I projected the class expectations and had us read through them again. Then I have a few disruptive students shouting things like "WOW, GLAD I'M LEARNING SO MUCH SCIENCE." How do I respond to things like that? I've emailed two student parents from that class (no response yet) and I feel like just generally the kids in the class don't respect me much and I'm not sure how to change that. A couple of the kids will roll their eyes at me or argue about things I ask them to do. I just feel like I really need to get on track with this class before things escalate even worse, but I've already focused so much on trying to teach them behavior expectations and rules that I'm not sure what else I can be doing. Any advice would be appreciated; this is a totally new age group for me.