Question

Which set correctly lists the major gases present in the primitive atmosphere?

Options

• \(O_2\), \(O_3\), \(CO\), and \(SO_2\)

• \(HCl\), \(H_2S\), \(SO_2\), and \(O_2\)

• \(H_2\), \(CH_4\), \(NH_3\), \(CO_2\), \(N_2\), and \(H_2O\) vapour

• \(He\), \(Ne\), \(Ar\), and \(Kr\)

Answer 1

The primitive (reducing) atmosphere contained hydrogen (\(H_2\)), methane (\(CH_4\)), ammonia (\(NH_3\)), carbon dioxide (\(CO_2\)), nitrogen (\(N_2\)), and water vapour (\(H_2O\)). Free oxygen was not present.