/6 Science Quiz (for 12 to 16 years old): Quiz 17 1 / 6Carbon, diamond and graphite are together called isomers isotopes allotropes isomorphs 2 / 6Heavy water is PH7 deuterium oxide rain water tritium oxide 3 / 6The gas usually filled in the electric bulb is carbon dioxide nitrogen oxygen hydrogen 4 / 6Chlorophyll is a naturally occurring chelate compound in which central metal is magnesium calcium copper iron 5 / 6Washing soda is the common name for Calcium carbonate Calcium bicarbonate Sodium bicarbonate Sodium carbonate 6 / 6Quartz crystals normally used in quartz clocks etc. is chemically a mixture of germanium oxide and silicon dioxide sodium silicate silicon dioxide germanium oxide Your score is 0% Restart quiz Next quiz Please rate the quiz Send feedback By WordPress Quiz plugin