Question

question 1 (multiple choice worth 4 points) (01 03r lc) which of the following was likely present in earths early atmosphere over four billion years ago? abundance of oxygen very cold temperatures presence of inorganic molecules low levels of ultraviolet radiation

Explanation:

• Abundance of oxygen: Early Earth's atmosphere had very little oxygen. Oxygen levels increased significantly later due to photosynthetic organisms.
• Very cold temperatures: Early Earth was hot, with volcanic activity and a molten surface in the Hadean eon (over four billion years ago).
• Presence of inorganic molecules: The early atmosphere likely had inorganic molecules like water vapor (\(H_2O\)), carbon dioxide (\(CO_2\)), methane (\(CH_4\)), ammonia (\(NH_3\)) etc. as suggested by theories of planet formation and early - Earth geochemistry.
• Low levels of ultraviolet radiation: There was no ozone layer (which absorbs UV radiation) in the early atmosphere, so UV radiation levels were high.

Answer:

Presence of inorganic molecules