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