Exam 9: Making Earth

There is direct geologic evidence about Earth's earliest crust.

What percent of a comet is water?

Two billion years ago, radioactive heat production was

Why is it more difficult to discern the formation processes of the continental crust versus the oceanic crust?

What evidence is there for the late delivery of water to an initially dry Earth?

Planetary differentiation relies upon

Is the accretion process of Earth over?

How did the core and mantle form?

Figure 9.9 -Using Figure 9.9 in your textbook, choose the option that sequences the elements according to what scientists think are the least abundant elements in the mantle to the most abundant elements in the mantle.

Evidence that scientists would not utilize to study Earth's formation is

Which observation suggests that the continental crust did not form by the same processes that presently occur on Earth?

Meteorites are called meteoroids when they land on the surface.

Although the iron sank to the core, most of the "strongly" iron-seeking elements remained behind.

Differentiation of planetary embryos results in denser ________ cores and less-dense ________ mantles.

Which of the following is a good analogy for planetary differention?

What explains the lack of volcanic gases, such as sulfur dioxide, hydrogen sulfide, and hydrogen chloride, in Earth's atmosphere?

Why is the inner core expanding?

Which of the following did not form in the hotter inner part of the solar system according to solar system theory?

What evidence do geologists have that Earth was once hotter than it is today?

Which planets contain mostly hydrogen atmospheres?