What is the gas composition of air?

Question

PPL(A) English - Private Pilot License - Meteorology - What is the gas composition of air?

QuizVDS · Accepted Answer

Oxygen 21 % Nitrogen 78 % Noble gases / carbon dioxide 1 %

QuizVDS · Answer

Oxygen 21 % Water vapour 78 % Noble gases / carbon dioxide 1 %

QuizVDS · Answer

Oxygen 78 % Water vapour 21 % Nitrogen 1 %

QuizVDS · Answer

Nitrogen 21 % Oxygen 78 % Noble gases / carbon dioxide 1 %

PPL(A) EN: What is the gas composition of "air"?