There is / are.....???

Here is my question,I wanna know if I want to make a question by using " Is/Are there..... " in case that I still don't know if something I am asking about does exist or not (you know, if it exists it could have more that one)I am confused cause many times when I found cases like this some writers use "Is" and the others use "Are".

Example 1: Is there / Are there any students in that room ?(supposing that I can't see it myself)

Example 2: Is there/ Are there any differences between these two words?

Which one should I use ?

Thanks you guys in advance...........