I got this book from my middle school library in like 7-8th grade, so it’s probably for younger kids.
The plotline was that a group of kids gain powers (I don’t remember how); I think the powers have something to do with being indestructible. The girl begins to go crazy towards the end and the group has to electrocute her. I believe she survives. I believe the girl is a new girl at their school. I could be wrong but I kind of remember the kids switching off having powers. Maybe they can’t die while they have the power?