How Did Oxygen (O₂) Get into Earth's Atmosphere

question 64

Multiple Choice

How did oxygen (O₂) get into Earth's atmosphere?

• A) It was released by life through the process of photosynthesis.
• B) It was captured from the solar nebula.
• C) It was outgassed from volcanoes.
• D) It came from chemical reactions with surface rocks.

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Definitions:

River Terrace

A flat, bench-like structure alongside a river, formed by the river cutting deeply into the land then retreating, leaving a raised platform.

Well-developed Soil

Soil that has undergone extensive formation processes, resulting in distinct layers and rich nutrient content.

Lava Flow

The movement of lava as it pours out and spreads over the land following a volcanic eruption.

Angular Unconformity

An unconformity (ancient erosion surface) in which the older, underlying strata dip more steeply or at a different angle than the younger, overlying strata.