ga arimasu / wa arimasu

[pacerier]

hi all, i've learnt that when you say something exists, you use abc ga arimasu

however why is it that when you ask if something exists, we use wa instead of ga:
abc wa arimasu ka?

can we say this:
abc ga arimasu ka?

 

[Toritoribe]

は・が issue... There are so many threads about the subject in this forum. Tae Kim's site also has it.

Introduction to Particles | Learn Japanese