/6 Science Quiz (for 12 to 16 years old): Quiz 18 1 / 6Which of the gas is not known as greenhouse gas? Methane Nitrous oxide Carbon dioxide Hydrogen 2 / 6Soda water contains carbonic acid carbon dioxide sulphuric acid nitrous acid 3 / 6The hardest substance available on earth is Platinum Diamond Gold Iron 4 / 6Potassium nitrate is used in fertiliser medicine salt glass 5 / 6Permanent hardness of water may be removed by the addition of sodium carbonate alum lime potassium permanganate 6 / 6Bromine is a highly inflammable gas red liquid black solid colourless gas Your score is 0% Restart quiz Next quiz Please rate the quiz Send feedback By WordPress Quiz plugin