MediumHard Science
What element did Joseph Priestley discover in 1774?
Riddle
What element did Joseph Priestley discover in 1774?
Choose an answer
A.Hydrogen
B.Nitrogen
C.Carbon Dioxide
D.Oxygen
Hint: It's a word with 6 letters, starting with "O".
Answer
Oxygen
Why this is the answer
Priestley isolated oxygen by heating mercuric oxide.
This riddle is filed under Science Riddles and rated Medium.