/7 Science Quiz (for 12 to 16 years old): Quiz 2 1 / 7The hardest substance available on earth is Platinum Gold Diamond Iron 2 / 7Quartz crystals normally used in quartz clocks etc. is chemically a mixture of germanium oxide and silicon dioxide germanium oxide sodium silicate silicon dioxide 3 / 7The gas usually filled in the electric bulb is oxygen hydrogen Nitrogen carbon dioxide 4 / 7Washing soda is the common name for Calcium bicarbonate Calcium carbonate Sodium bicarbonate Sodium carbonate 5 / 7Which of the gas is not known as green house gas? Methane Hydrogen Carbon dioxide Nitrous oxide 6 / 7What is the primary cause of climate change? Natural factors Human activity Animal activity Climate change is primarily caused by human activity, particularly the burning of fossil fuels and deforestation.7 / 7Bromine is a red liquid colourless gas highly inflammable gas black solid Your score is 0% Restart quiz Next quiz Please rate the quiz Send feedback