I have a new situation: 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. But I can use this background: 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. What is an answer for this question: Which element would have less protons in the nucleus, element A or element B?
Ans: element B

I have a new situation: Tom and John are both pool owners. Tom prefers to use sodium bisulfate in his pool because he enjoys the smell. John, however, prefers using sodium carbonate in his pool because he believes it helps keep pests away. But I can use this background: We all enjoy a cool dip in a swimming pool on a hot day, but we may not realize the work needed to keep that water safe and healthy. The ideal pH for a swimming pool is around 7.2. The pH will change as a result of many factors. Adjustment can be accomplished with different chemicals depending on the tested pH. High pH can be lowered with liquid HCl (unsafe material) or sodium bisulfate. The bisulfate anion is a weak acid and can dissociate partially in solution. To increase pH, use sodium carbonate. The carbonate anion forms an equilibrium with protons that results in some formation of carbon dioxide. What is an answer for this question: Whose pool will have higher levels of carbon dioxide?
Ans: John

I have a new situation: Two twin sisters, Bianca and Rosa, were exposed to high levels of air pollution. While Bianca was exposed mostly to indoor pollution, Rosa was heavily exposed to outdoor pollution. But I can use this background: Recall that air pollution is due to chemical substances and particles released into the air mainly by human actions. When most people think of air pollution, they think of the pollution outdoors. But it is just as easy to have indoor air pollution. Your home or school classroom probably doesn't get much fresh air. Sealing up your home reduces heating and cooling costs. But this also causes air pollution to stay trapped indoors. And people today usually spend a majority of their time indoors. So exposure to indoor air pollution can become a significant health risk. What is an answer for this question: Which sister was more exposed to air pollution because of cutting cooling costs?
Ans: Bianca

I have a new situation: Two brothers Syd and Dan went to college. Syd studied plate tectonics and mantle melting. His brother Dan got to study types of soil and pedology. But I can use this background: Mantle melting can come about three ways: (1) when the temperature rises, (2) if the pressure lowers (which lowers the melting point), and (3) if water is added, which lowers the melting point. Two of these (1 and 3) might explain why there are volcanoes at convergent plate boundaries the temperature of the subducting plate increases as it sinks into the hot mantle (1). Sediments lying on top of the subducting plate contain water. As the sediments subduct, the water rises into the overlying mantle material. This lowers the melting temperature of the mantle (3). When the mantle above the subducting plate melts, volcanoes form above it. This leads to volcanoes in an island arc or continental arc. What is an answer for this question: Which brother studied less about the influence sediments have on mantle melting?
Ans: Dan