I disagree, Washington D.C. is so small that it's even smaller than Rhode Island, the only state that has a less population than Washington D.C. is Wyoming but that's a big state so it makes sense but a tiny state with such a small amount of people doesn't make much sense,

Because we haven't had the technology to see inside the earth it's still very hard for us to know things for sure but it's hard to predict what's 100's of miles beneath your feet without very very advanced technology

If this happens then a state would be the capitol of the united states?

yes! its so rude yet it happens so much