H "to" O is doubtful to me...Though a great creative answer none the less! (Seems a little too obvious though)

Here is an alternative:

7 letters before H-------11 letters after O

7Eleven!! (As in where you get your big gulp's from!) A 10 year old would definitely buy his slurpee's there!! And there is no doubt that 7Eleven is an object, no need for a formal education here!!

After thinking about it, I think this IS the answer. Maybe not, however 7Eleven seems more logical to me.

I have to say, most 10 year old's would know 7Eleven before knowing H2o

Cheers!

 

Water H "to" O. At first I thought it might be a 7 letter scrabble word but there aren't any combinations.

 

I believe it's Water.