/6 Science Quiz (for 12 to 16 years old): Quiz 18 1 / 6Bromine is a black solid red liquid colourless gas highly inflammable gas 2 / 6Potassium nitrate is used in salt fertiliser glass medicine 3 / 6Which of the gas is not known as greenhouse gas? Nitrous oxide Carbon dioxide Hydrogen Methane 4 / 6Permanent hardness of water may be removed by the addition of lime sodium carbonate alum potassium permanganate 5 / 6Soda water contains nitrous acid sulphuric acid carbonic acid carbon dioxide 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