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