/6 Science Quiz (for 12 to 16 years old): Quiz 8 1 / 6Permanent hardness of water can be removed by adding washing soda bleaching powder potassium permanganate chlorine 2 / 6The filament of an electric bulb is made of graphite nichrome tungsten iron 3 / 6The two elements that are frequently used for making transistors are niobium and columbium iridium and tungsten silicon and germanium boron and aluminium 4 / 6In fireworks, the green flame is produced because of potassium barium sodium mercury 5 / 6Diamond is an allotropic form of carbon sulphur germanium silicon 6 / 6Marsh gas is hydrogen ethane methane nitrogen Your score is 0% Restart quiz Next quiz Please rate the quiz Send feedback By WordPress Quiz plugin