Soru

### Origin of Earth's Water

How Earth acquired its water is a subject of debate among planetary scientists. Two models describe different origins:

Model 1 (Asteroid Delivery)
Earth initially formed dry because the heat of the early Sun drove volatile compounds outward. Later, water-rich carbonaceous chondrite asteroids from the outer solar system collided with the cooling Earth, depositing water. The Deuterium-to-Hydrogen ($D/H$) ratio of these asteroids matches the ratio found in Earth's current oceans ($1.5 \times 10^{-4}$).

Model 2 (Nebular Ingestion)
Earth acquired water during its formation. The proto-Earth was surrounded by hydrogen-rich solar nebula gas. This primordial gas was dissolved directly into the magma ocean of the growing planet, where the hydrogen reacted with iron oxides in the mantle to form water. This model predicts that early Earth water initially had a $D/H$ ratio of $0.2 \times 10^{-4}$.

Based on the passage, match each statement about the origin of Earth's water to the model(s) it describes.