Multi-choice Question One of the following is not a physical property of hydrogen Answers Option 1 Hydrogen is odourless Option 2 Hydrogen is less dense than air Option 3 Hydrogen is colourless Option 4 Hydrogen has a sweet smell Option 5 Feedback Wrong Wrong Wrong Correct Option Wrong Solution Wrong (Feedback) Wrong (Feedback) Wrong (Feedback) Correct Option (Feedback) Wrong (Feedback)