When nurses start acting like you mentioned, it's time to go. Actually, it's time to go before that happens. Nurses do need to vent to each other sometimes. It's just necessary, but it needs to be done far away from the patient, not within ear shot. Nurses burn out all of the time, and some decide to leave and try a different nursing position. Others don't. People get comfortable where they are, and some people get so comfortable that they don't want to learn a new position, and feel like the new guy again even if they have lost their compassion and hate their job. I can understand that on some level, but that's just not me. If I really hate my job, I will look elsewhere. In fact, I'm looking for a different position, but it's not because I hate my job. I actually enjoy it, but that's not applicable here.
I have also seen great nurses that are burnt out. They still treat their patients like they should, with compassion, and care. But, all units are not the same, so don't let that one experience scar you. Even if you end up on a floor like that, it will only make you stronger. Get through it, do your year, and then move on to greener pastures. And, don't participate in the gossip.