Argon (Ar\text{Ar}Ar) and carbon dioxide (CO2\text{CO}_2CO2) are two of the minor gases present in today's dry atmosphere. Using their standard approximate percentages by volume in today's dry atmosphere, what is the ratio of the volume of argon to the volume of carbon dioxide?
2.252.252.25
22.522.522.5
225225225
525525525
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.