Normal for bearded dragon?

  I purchased a new bearded dragon today, and hes eaten and everything, but he's keepig his mouth partially open. Is there something wrong with that or is it fine? He's about 8-10 inches long, I don't know how old. How much should he be eating?
He's just venting, it is how they cool off. Make sure one side of the tank is hot, 100-110 *, while the other side is cooler, 80-90 *. He should be eating as many crickets a day as he can, at least 2x a day. Also make sure you are offering greens, veggies, and fruits. Look up some more information about dragons, there are many good websites online.
My beardy keeps her mouth open all the time when basking, it has to do with the heat. And as of feeding, feed him till he dont eat no more, beardys eat a lot. Feed as many crickets as he will take, make sure they are no bigger then the distance between his eyes
the tank might be to hot so hes keeping his mouth open