Which statement about the density of warm water is most likely correct? (2 points)

Which of the following is true about the origin of the salts in Earth’s oceans? (2 points)

What is most likely true about ocean temperatures surrounding Australia, which is marked by the star in the following map? (2 points) Public Domain

Which of the following ocean-floor features is associated with areas where oceanic crust is broken down? (2 points)

Which of the following is a term used to describe the shallow location near the shore where water covers the continent? (2 points)

The graph below shows the radioactive decay of an isotope of strontium. Based on the graph, what is the half-life of strontium? (4 points)

A substance has a half-life of 100,000 years and an initial mass of 1,000 grams. How many years will pass before only 250 grams of the substance’s parent material is left? (2 points)

The graph below shows the radioactive decay of an isotope of carbon. Based on the graph, what is the half-life of carbon? (4 points)

Which of the following reduces the number of protons in the nucleus of an atom by 2? (2 points)

A rubidium isotope has a half-life of almost 50 billion years. Given that scientists estimate Earth’s age to be 4.6 billion years, what is the most likely percentage of parent to daughter isotopes of this element currently existing on Earth? (2 points)