yellow tang + flame angel

I don't know much about that pairing but I do know that those who do will want to know what your whole setup is, tank size, other fish, reef? etc...

I would say yes it will be, at least based on what happened in my brothers first tank(was a 55 now he has a 135). His yellow tang killed his Bi-color angel two weeks after he put it in the tank. I'd say its definitely a risk, so why not get a few more smaller fish? Royal grammas are gorgeous, maybe a cardinal or goby???

I also think that tank will be too small to house a tang. Tangs need a bigger tank.

In general those two fish do fine together. But I agree your tank is too small. It is recommended a 4 foot tank minimum to keep up with their activity level. Anyway, hope this helps and good luck!