An environmental chemist is calibrating a high-precision gas chromatograph using a sample of clean, dry air collected at sea level.
Which of the following options correctly ranks the five most abundant gases in Earth's modern, dry atmosphere in descending order of their volume fraction?
N2>O2>CO2>Ar>Ne\text{N}_2 > \text{O}_2 > \text{CO}_2 > \text{Ar} > \text{Ne}N2>O2>CO2>Ar>Ne
N2>O2>Ar>CO2>Ne\text{N}_2 > \text{O}_2 > \text{Ar} > \text{CO}_2 > \text{Ne}N2>O2>Ar>CO2>Ne
N2>O2>Ar>Ne>CO2\text{N}_2 > \text{O}_2 > \text{Ar} > \text{Ne} > \text{CO}_2N2>O2>Ar>Ne>CO2
O2>N2>Ar>CO2>He\text{O}_2 > \text{N}_2 > \text{Ar} > \text{CO}_2 > \text{He}O2>N2>Ar>CO2>He
97 exam-style questions on Edexcel GCSE Chemistry 9.2 Earth and atmospheric science, covering 9.2.1 The Earth's early atmosphere, 9.2.2 How the atmosphere evolved, 9.2.3 Chemical test for oxygen, and 9.2.4 The greenhouse effect and climate change. Each one has a worked solution and a mark scheme showing where the marks go.