Given the background: As a young man, Bohr worked in Rutherford's lab in England. Because Rutherford's model was weak on the position of the electrons, Bohr focused on them. He hypothesized that electrons can move around the nucleus only at fixed distances from the nucleus based on the amount of energy they have. He called these fixed distances energy levels, or electron shells. He thought of them as concentric spheres, with the nucleus at the center of each sphere. In other words, the shells consisted of sphere within sphere within sphere. Furthermore, electrons with less energy would be found at lower energy levels, closer to the nucleus. Those with more energy would be found at higher energy levels, farther from the nucleus. Bohr also hypothesized that if an electron absorbed just the right amount of energy, it would jump to the next higher energy level. Conversely, if it lost the same amount of energy, it would jump back to its original energy level. However, an electron could never exist in between two energy levels. These ideas are illustrated in the Figure below . and the situation: Greg was studying Bohr's model. He found it helpful to categorize different scenarios in the model. First, he labeled electron with higher energy as cat A, and electron with lower energy as cat B. Then he labeled electron that gained energy as cat C, and election that lost energy as cat D. Answer the following question: Would cat B be closer to or farther from the nucleus than cat A?
Ans: closer

Given the background: White blood cells also make chemicals that cause a fever. A fever is a higher-than-normal body temperature. Normal human body temperature is 98.6F (37C). Most bacteria and viruses that infect people reproduce fastest at this temperature. When the temperature is higher, the pathogens cannot reproduce as fast, so the body raises the temperature to kill them. A fever also causes the immune system to make more white blood cells. In these ways, a fever helps the body fight infection. and the situation: Jim and Pam are a married couple who both have the same illness. They are at home from work today and are in the process of taking their temperatures so they know if they need to go to the doctor or not. After using the thermometer, they learn that Pam has a much higher fever than Jim. They decide they should take Pam to the doctor to get her looked at. Answer the following question: Does Jim have more or less white blood cells than Pam?
Ans: less

Given the background: In the U.S., the majority of electricity is produced by burning coal or other fossil fuels. This causes air pollution, acid rain, and global warming. Fossil fuels are also limited and may eventually run out. Like fossil fuels, radioactive elements are limited. In fact, they are relatively rare, so they could run out sooner rather than later. On the other hand, nuclear fission does not release air pollution or cause the other environmental problems associated with burning fossil fuels. This is the major advantage of using nuclear fission as a source of energy. and the situation: Park city used fossil fuels to produce their electricity. They were less conscious about the environment than their neighbors from Lake city. People from Lake city used nuclear fission as an energy source. Answer the following question: Which city burned less coal for their energy needs?
Ans: Lake

Given the background: The dangers of global warming are being increasingly studied by a wide global consortium of scientists. These scientists are increasingly concerned about the potential long-term effects of global warming on our natural environment and on the planet. Of particular concern is how climate change and global warming caused by anthropogenic, or human-made releases of greenhouse gases, most notably carbon dioxide, can act interactively, and have adverse effects upon the planet, its natural environment and humans' existence. It is clear the planet is warming, and warming rapidly. This is due to the greenhouse effect, which is caused by greenhouse gases, which trap heat inside the Earth's atmosphere because of their more complex molecular structure which allows them to vibrate and in turn trap heat and release it back towards the Earth. This warming is also responsible for the extinction of natural habitats, which in turn leads to a reduction in wildlife population.The most recent report from the Intergovernmental Panel on Climate Change (the group of the leading climate scientists in the world) concluded that the earth will warm anywhere from 2.7 to almost 11 degrees Fahrenheit (1.5 to 6 degrees Celsius) between 1990 and 2100. and the situation: Two identical planets, Norlon and Bothar, have been discovered in a neighboring galaxy of ours. These two planets have the same type of atmosphere as Earth and are extremely similar to Earth in terms of topography and even species of animals that live on them. The main difference is that Norlon is inhabited by a species very similar to humans that emit a lot of carbon dioxide into the atmosphere. Bothar, however, has no such species on its planet. Answer the following question: Which of the newly discovered planets will sustain life for a longer amount of time?
Ans: Bothar