Atmospheric chemists think that earth’s first atmosphere
a. was very similar to today’s atmosphere.
b. contained no oxygen atoms.
c. consisted of carbon in the form of carbon monoxide.
d. consisted of carbon in the form of carbon dioxide. e. contained nitrogen in the form of ammonia and nitrogen gas.

I think the best answer from the choices is option B. Atmospheric chemists think that Earth’s first atmosphere contained no oxygen atoms. It was believed that the early atmosphere of the Earth was due to the volcanic activities which are not known to produce oxygen atoms. Therefore, chemists think that there were no atoms of oxygen.

Adozen is 1221/12 = 1.751.75 x 12 = 21therefore, 1.75 is the answer.