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