Tadpoles vs goldfish?

Of course they will survive. You should know that tadpoles grow very quick and soon you will notice two hind legs they would grow and their tail shorten giving them the shape of a toad, then they will want to hop out of the bowl because their life is supposed to be terrestrial as well. Tadpoles are carnivores and their waste might cause the ammonia level in the bowl to rise. I appreciate your concern for the lives of the tadpoles and your attempt to protect them, but sometimes it's good respect nature as it takes its own course, birds eating tadpoles is one aspect of the mother nature's food chain. But if you have to keep the tadpoles then place them in a different tank, or it could even be a plastic a container, for a while but you are going to have to let them go eventually.