Is my snail dead??? PLEASE HELP ASAP!!!?

my ramshorn was just put into the tank. he hasn't come out of his shell, he didn't in the bag either. they guy at the store had just got him, and he was just sitting on in the bag, like the rest of them. i put him in a place where he could easily grap onto the wall, but he still isn't comming out. my apple snail was latched onto the bag, and is now going over my tank looking for algae (and i will say he is finding a lot of it). if my ramshorn is dead, is he hurting the other fish? i just did a 25% water change, and i plan to do one tomorro two, since both this ramshorn snail, an apple snail, and another neon tetra were just introduced to the tank. everyone in the tank is acting like theyve been in there for years--except for the ramshorn. he is just sitting there. wat should i do??? can i wait till morning?