Exam 4: The Habitability of Earth

Rocks are found on the surface of another planet which appear to have once been transformed at high temperatures and pressures deep within the planet. Given this, they are most likely to be classified as

Analysis of rocks returned from the lunar maria during the Apollo program suggest they formed

The Earth's geological time scale is divided into four main

When an igneous rock is melted and then re-solidifies it turns into

Fragments of rocks formed due to erosion settle out to form layers of

For life to have existed continually on the Earth for the past 4 billion years, the oceans must have been

A sterilizing impact is one during which

Given the Earth's larger size and strong gravity, the Earth's surface should have more impact craters than the Moon. However, it has very few. Why is this?

A rock sample contains 1/2 microgram of the parent radioactive isotope U-235 and 1/2 microgram of its daughter isotope Pb-207. If the half-life of this decay is 700 million years, how old is this rock?

Over geological time periods, the Earth's climate has been

When heat and pressure are applied to a sedimentary rock it turns into

A radioactive isotope with an atomic number of 90 undergoes beta decay. What is the atomic number of the daughter nucleus?

Why can't the carbon dioxide cycle easily correct for the increasing amounts of carbon dioxide introduced into our atmosphere by industrialization?

In which eon of Earth's history did the heavy bombardment occur?

In alpha decay,

Given that all bodies in the solar system should have suffered equally from collisions during the period of early bombardment, if we find a body with relatively few craters on its surface we deduce that

A possible spike in the number of impacts in the inner solar system about 4 billion years ago may have mostly likely been due to

In beta decay,

The Phanerozoic eon is divided into three main

Subduction on the Earth is the process by which