Global temperatures have increased over the last 100 years. What evidence is there that human activities are at least partially responsible for this increase?

This is the energy diagram for the magnesium–oxygen reaction.    Image Description Graph of the magnesium-oxygen energy curve with energy (y-axis) versus the extent of reaction (x-axis). The energy line starts level then increases before reaching its peak energy around the middle of the reaction, then decreasing in energy and leveling off well below the initial energy level line. Sodium will also react with oxygen. However, unlike magnesium, sodium begins to react as soon as it is exposed to oxygen and produces very little heat and no visible light. Which of these curves best represents the sodium–oxygen reaction compared with the magnesium-oxygen reaction? (The curve for magnesium + oxygen is shown using a dotted line for reference.)    Image Description Five energy diagrams. Diagram A is as follows: The sodium-oxygen energy curve starts by increasing twice as much as the magnesium-oxygen line before reaching its peak and decreasing to below the initial energy line. The final level of sodium-oxygen energy is less than the magnesium-oxygen energy level. Diagram B is as follows: The sodium-oxygen energy curve starts by increasing more than the magnesium-oxygen line, reaching its peak a little after magnesium-oxygen before decreasing and leveling off, with its final energy above the initial energy line. The final level of sodium-oxygen energy is much greater than the magnesium-oxygen energy level. Diagram C is as follows: The sodium-oxygen energy curve starts by increasing a little then going back to the initial energy level by the middle of the reaction. The line keeps decreasing before rounding off and heading back to the initial energy line at the end of the reaction. The final level of sodium-oxygen energy is greater than the magnesium-oxygen energy level. Diagram D is as follows: The sodium-oxygen energy curve starts by increasing, but not as much as the magnesium-oxygen energy line, before rounding off and decreasing to below the initial energy line. The final level of sodium-oxygen energy is above the magnesium-oxygen energy level. Diagram E is as follows: The sodium-oxygen energy curve starts by increasing a little before decreasing a great amount below the initial energy line before rounding back up and increasing in energy back above the initial energy line. It begins to taper back to a decreasing line as the reaction ends. The final level of sodium-oxygen energy is greater than the magnesium-oxygen energy level.

A divergent plate margin bisects the Red Sea. What will happen to the Red sea as a result of the presence of this diverging plate boundary?   

The outer planets are much more massive and much lower density than the inner planets. What conditions in the disk of gas and dust that surrounded the protostar that became the sun led to the difference between the Jovian and Terrestrial planets?

The age provided for rock A is actually the age of what?

For generating nuclear energy, fusion experiments use the smallest nuclei, isotopes of hydrogen, while fission experiments use very large nuclei. Why?

This graph shows nucleon mass versus atomic number. Image Description Graph of average nucleus mass (y-axis) versus the atomic mass number (x-axis). The graph starts off with an average nucleus mass of 1.008 and decreases to 1.001 with an atomic mass number of 5. The line goes back up to 1.0025 until the atomic mass number is 10 before it decreases to just below 0.999 at around an atomic mass number of 55 before gradually increasing to 0.999 at atomic mass number 100, 0.9995 at atomic mass number 150, 1 at atomic mass number 210, and 1.0005 at atomic mass number 250. The next three questions deal with this graph.

Rock layers N and J occur on either side of the unconformity labeled I. What can you conclude from the cross section about the relative ages of layers N and J?

The graph of nucleon mass versus atomic number ends fairly abruptly. Why aren’t there any atoms with atomic masses of 300?

The following four questions test your understanding of the principles of relative dating. In the cross section below, intrusion A is an igneous rock formation radiometrically dated at 37 million years, H is a fault, and O and I are unconformities. In the following four questions you are asked to use the principles of relative dating to come to conclusions about the rock layers. Image Description Diagram of several cross-sections. Starting from the top, an F layer runs horizontally across the surface. Beneath the layer F are several other layers going diagonally down across the screen. Four layers meet layer F from below. Starting on the left side of layer F is layer J. To the right of layer J is the unconformity line labeled I. To the right of the unconformity line I is the layer N, K, and B with B being the rightmost layer touching layer F. Going back to the layer J, which is below the unconformity line I, there is a portion of the igneous rock intrusion A in the middle of J. The A intrusion spans from the unconformity line I down to the bottom of the image. To the left of the instrusion A and below the layer J lies layer D and M, with layer M beneath layer D. Beneath layer M lies the unconformity line labeled O. In the middle of the unconformity line O is a fault labeled H. The fault line H runs from line O to the bottom of the screen, offsetting the last four layers C, L, G, and E, with E being the last layer.