Question

does a bowl of water kept in vacuum when heated externally produce steam making the vacuum a non vacuum?

Answer 1

In vacuum , the vapour pressure is reduced and thus, the boiling point is also decreased.Thus, a part of water gets evaporated.These evaporated molecules of water draw energy from the rest of the water molecules to get evaporated.Almost 70% of water will freeze.
If heat is supplied to the water, then the water won't freeze at all and all of it will get boiled and create vapours, thus creating a space that won't be a vacuum.