Background: Some materials have negative heats of solution; the dissolution of one of these solutes in water is an exothermic process. Heat is released, causing a net increase in the temperature of the solution. Conversely, other substances have positive heats of solution. For example, the dissolution of potassium nitrate in water is an endothermic process. The resulting absorption of energy causes the solution to become colder. Calculations involving heats of solutions follow the same basic approach that we have used with other enthalpy problems. Paragraph: A scientist is in the lab testing mixing water with different chemicals. While working with chemical A he notes that the water becomes colder after combining them. With chemical B the water becomes much warmer. Given the paragraph above, please answer correctly the following question: Given the changes in temperature, does chemical A cause an exothermic process or an endothermic process?
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Answer: exothermic

Background: East Antarctica is colder than its western counterpart because of its higher elevation. Weather fronts rarely penetrate far into the continent, leaving the centre cold and dry. Despite the lack of precipitation over the central portion of the continent, ice there lasts for extended periods. Heavy snowfalls are common on the coastal portion of the continent, where snowfalls of up to 1.22 metres (48 in) in 48 hours have been recorded. Paragraph: Joe lived in East Antarctica while his buddy Jim lived in West Antarctica. They were both into collecting rare specimens of plants and wildlife. They would often complain about the weather. Given the paragraph above, please answer correctly the following question: Which friend lived at a lower elevation?
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Answer: Jim

Background: Human beings invented agriculture about 10,000 years ago. This provided a bigger, more dependable food supply. It also allowed people to settle down in villages and cities for the first time. Birth rates went up because there was more food and settled life had other advantages. Death rates also rose because of crowded living conditions and diseases that spread from domestic animals. Because the higher birth rates were matched by higher death rates, the human population continued to grow very slowly. Paragraph: David was studying human history. He selected two specific eras of human history, era A and era B. Era A was before humans had invented agriculture. And, era B was after the invention of agriculture. He noticed that human societies had changed dramatically after the invention of agriculture. Given the paragraph above, please answer correctly the following question: Did era A have higher or lower death rate than era B?
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Answer:
lower