Which element is the main component of the Earth's atmosphere?

---

=> What is the chemical symbol for gold?
=> Which gas is responsible for the greenhouse effect?
=> What is the atomic number of hydrogen?
=> Which acid is found in lemons?
=> What is the chemical formula for water?
=> Which element is the main component of the Earth's atmosphere?
=> What is the pH of a neutral solution?
=> Which gas is produced during photosynthesis?
=> What is the chemical formula for methane?
=> What is the chemical name for baking soda?