question_answer

Which of the following was most likely to have been absent in free form in the primordial atmosphere at the time of origin of life [CPMT 1974, 76, 78, 82, 90, 98; AFMC 1985; NCERT 1971, 72; KCET 1998; MP PMT 1994, 99; CBSE PMT 2004; BVP 2004; BCECE 2005]

A)          \[{{O}_{2}}\]

B)            \[C{{H}_{4}}\]

C)            \[{{H}_{2}}\]

D)            \[N{{H}_{3}}\]