Given a scientific passage and an answer, generate a question for the given answer.
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Question: Passage: The force of gravity is called weight. Near the surface of a planet, it has magnitude and is directed perpendicular to its surface. This is different from the Gravitational Constant, and differs from planet to planet. Answer: weight

Answer: What is the force of gravity called?

Question: Passage: Greenhouse gases include CO 2 , H 2 O, methane, O 3 , nitrous oxides (NO and NO 2 ), and chlorofluorocarbons (CFCs). All are a normal part of the atmosphere except CFCs. The table below shows how each greenhouse gas naturally enters the atmosphere ( Table below ). Answer: greenhouse gases

Answer: Co 2 , h 2 o, methane, o 3 , nitrous oxides (no and no 2 ), and chlorofluorocarbons (cfcs) are known as what type of gases?

Question: Passage: 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. Answer: exothermic process

Answer:
Some materials have negative heats of solution; the dissolution of one of these solutes in water is called?