Things that start with IO

I thought of this AFTER my visit to Iowa. Here is a game to identify some possibly famous or well known names, places, words that begin Io:

Io – Moon of Jupiter

Ion – Electrically charged atom

Iolanthe – Operetta by Gilbert and Sullivan

Ionesco – French playright, i.e., Rhinocerous

Iowa – Midwestern US state

Iodine – Element; used in medicine as an antiseptic

IOU – Written acknowledgement of a debt

Iota – A very small quantity; also, ninth letter of the Greek alphabet

Ionia – Ancient region of Asia Minor colonized by the ancient Greeks

Ionosphere – A region of the earth’s atmosphere