I read this background article the other day: Greenhouse Effect: The solar energy reaching the surface of the Earth is concentrated in short wavelengths, which can easily penetrate the greenhouse gases, such as carbon dioxide and methane. The Earth, however, is cooler than the sun and it radiates its heat in the form of energy in the far infrared range. These longer wavelengths are partially absorbed by the greenhouse gases and some of the solar heat is returned to Earth. At a certain temperature these processes are in equilibrium and the surface temperature of the Earth is stable. However, if more greenhouse gases are put in the atmosphere the amount of trapped terrestrial radiation increases, leading to an increase in global temperature. I am facing a new situation today: Two meteorologists were good friends and discussed diverse issues weekly. This week they will talk again. Tim read about the Greenhouse Effect while Norm read about the mini-Ice ages. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which friend learned less about solar energy reaching the surface of the Earth?
Ans: Norm

I read this background article the other day: Start right above point on the temperature axis and follow the red line vertically. At very low pressure, the particles of the substance are far apart from one another and the substance is in the gas state. As the pressure is increased, the particles of the substance are forced closer and closer together. Eventually the particles are pushed so close together that attractive forces cause the substance to condense into the liquid state. Continually increasing the pressure on the liquid will eventually cause the substance to solidify. For the majority of substances, the solid state is denser than the liquid state and so putting a liquid under great pressure will cause it to turn into a solid. The line segment represents the process of sublimation, where the substance changes directly from a solid to a gas. At a sufficiently low pressure, the liquid phase does not exist. The point labeled is called the triple point . The triple point is the one condition of temperature and pressure where the solid, liquid, and vapor states of a substance can all coexist at equilibrium. I am facing a new situation today: Dan is conducting a research to see how a substance behaves in varying pressure. First, he selects a gaseous substance in very low pressure. He calls it as case A. Then he increases the pressure. He calls it case B. Finally, he increases the pressure even further. He calls it case C. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which case would see less distance between particles, case B or case C?
Ans: case C

I read this background article the other day: The general trend in electronegativity is that the value increases from left to right across a row in the periodic table and decreases down a column. The most electronegative element is fluorine, which has a value of 4.0. As discussed in the lesson "Trends in the Periodic Table," electronegativity increases across a row as the number of protons in the nucleus increases and therefore has a stronger pull. Electronegativity decreases down a column due to an increased effect of electron shielding in larger atoms. I am facing a new situation today: Mike has to learn more about the periodic table for his chemistry exam. To make things easier for him he chose two elements from the table, element A and element B. Element A has higher electronegativity and element B has lower eletronegativity. David found it easier to learn about elements by comparing their properties. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Where element B most likely be across the column, up or down?
Ans: down

I read this background article the other day: Many respiratory diseases are caused by pathogens. A pathogen is an organism that causes disease in another organism. Certain bacteria, viruses, and fungi are pathogens of the respiratory system. The common cold and flu are caused by viruses. The influenza virus that causes the flu is pictured below ( Figure below ). Tuberculosis, whooping cough, and acute bronchitis are caused by bacteria. The pathogens that cause colds, flu, and TB can be passed from person to person by coughing, sneezing, and spitting. Illnesses caused by bacteria can be treated with antibiotics. Those caused by viruses cannot. I am facing a new situation today: The doctors studied two groups of people, group one which included people with respiratory diseases caused by viruses, and group two, which had people with respiratory diseases caused by bacteria. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which group didn't include people that had the flu?
Ans: group two