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