Yes, in that situation an is correct as uranium starts with a vowel and starts with a vowel-like sound.

@jansuki (View Post)

1: You didn't answer the actual question asked.
2: It's not correct, uranium is pronounced "you-rane-ium" and uses "a". You don't say "an yellow ball"

3: Are you referring to actual uranium penetrators, as in real life, that make use of uranium's high density and hardness to penetrate targets? That concept isn't really applicable in TPT, since there is no kind of ballistics simulation or concept of "hardness". There's a type of weapon that utilizes uranium and a constant pressure source to penetrate into bunkers by utilizing the uranium as a heat source that sinks into the lava and heats from within. Is that what you're referring to? 

@wisco11 (View Post)

 draw some URAN and use PROP to make its vx very high.Remember to fill the whole screen with EHOL :D

@wisco11 (View Post)

 It gradually loses velocity,yes