"Apa" has a definite article, so "the water" should be an acceptable answer. Obviously, this can be used for a general fact, but it can also be used, say, if someone wants to state that "this water" contains oxygen and hydrogen, and nothing more.
It's accepted now.
It is a diferent kind of water, containing "hidroghen"...
The pronounciation of "hydrogen" is wrong.
Thank you. I was wondering why it was pronounced like hidroghen