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C1 Air quality
Twenty First Century Science
Question | Answer | Question | Answer | Question | Answer |
---|---|---|---|---|---|
real difference | you can be sure that the difference between two mean values is real if their ranges do not overlap | molecule | two or more atoms bonded together | nitogen dioxide | a gas which causes acid rain and makes breathing problems worse |
best estimate | the mean of a set of data | catalyst | speeds up a chemical reaction without being used up itself | carbon dioxide | a gas produces when fossil fuels are burned |
accuracy | how close a measurement is to the true value | element | a substance made from just one type of atom | sulphur dioxide | a gas which causes acid rain |
mean value | the average value | combustion | a chemical reaction with oxygen (burning) | methane | a gas produced by cows and rice fields which causes the greenhouse effect |
range | difference between the highest and lowest value in a set of measurements | reactants | chemical which react together | emissions | a polluting gas given out from a chemical reaction |
outlier | an odd measurement, very different from the rest, taht you suspect is wrong | products | new chemicals formed atthe end of a chemical reaction | primary pollutant | a harmful chemical that human activity adds directly to the atmosphere |
hydrocarbons | a chemical made from carbon and hydrogen atoms | particulates | microscopic soot particles | atom | smallest particle of a substance |