Answer:
planetesimal is (astronomy) any of many small, solid astronomical objects, that orbit a star and form protoplanets through mutual gravitational attraction while planet is (astronomy) a body which orbits the sun directly and is massive enough to be in hydrostatic equilibrium (effectively meaning a spheroid)
Answer:
The salt in the oceans comes from weathering and the erosion of the earth's crust.
Explanation:
The weathering can be described as the breaking down of rocks.
During the weathering of rocks, minerals will be dissolved from the land and salt is one of them. These minerals (salt included) will then be delivered into the oceans by erosion of the Earth's crust.
Erosion can be aided by wind, ice or water. Erosion removed weathered materials. When these weathered materials are removed, new materials (rocks) will be exposed to weathering thereby promoting continuous weathering processes
Answer:
four billion years ago the earth had a layer of ozone gas
