Short answers, pulled from the story.
The Greek word chaos means emptiness, vast void, chasm, or abyss. It comes from verbs that mean to gape or be wide open and connects to Proto-Indo-European roots found in Old English words for yawn.
Pherecydes of Syros interpreted chaos as water during the 6th century BC. He saw it as formless matter capable of differentiation before any other forms emerged.
Hermann Gunkel published Schöpfung und Chaos in Urzeit und Endzeit on the 1st of January 1895. This work linked Genesis to Babylonian cosmology and influenced later scholarly debates about biblical terms.
Jan Baptist van Helmont coined the term gas in chemistry during the 17th century by deriving it directly from Paracelsian notions of chaos. He stated halitum illum Gas vocavi near ancient secret Chao to explain this connection.
The Hebrew phrase tohu wa-bohu may refer to non-being or formlessness before creation according to scholars debating Genesis 1:2. Some reject associations between biblical narratives and Babylonian myths entirely while others link them semantically.