Given a scientific passage and an answer, generate a question for the given answer.

Input: Consider Input: Passage: Elements and Compounds Any sample of matter that has the same physical and chemical properties throughout the sample is called a substance. There are two types of substances. A substance that cannot be broken down into chemically simpler components is an element. Aluminum, which is used in soda cans, is an element. A substance that can be broken down into chemically simpler components (because it has more than one element) is acompound (Figure 1.2 "The General Steps of the Scientific Method"). Water is a compound composed of the elements hydrogen and oxygen. Today, there are about 118 elements in the known universe. In contrast, scientists have identified tens of millions of different compounds to date. Answer: substance

Output: Any sample of matter that has the same physical and chemical properties throughout the sample is called what?

Input: Consider Input: Passage: 41.4 Nitrogenous Wastes Ammonia is the waste produced by metabolism of nitrogen-containing compounds like proteins and nucleic acids. While aquatic animals can easily excrete ammonia into their watery surroundings, terrestrial animals have evolved special mechanisms to eliminate the toxic ammonia from their systems. Urea is the major byproduct of ammonia metabolism in vertebrate animals. Uric acid is the major byproduct of ammonia metabolism in birds, terrestrial arthropods, and reptiles. Answer: urea

Output: When vertebrate animals metabolize ammonia what is the primary byproduct that is produced?

Input: Consider Input: Passage: Collisions between gas particles and between particles and the container walls are elastic collisions . An elastic collision is one in which there is no overall loss of kinetic energy. Kinetic energy may be transferred from one particle to another during an elastic collision, but there is no change in the total energy of the colliding particles. Answer: elastic
Output: What sorts of collisions do not result in an overall loss of kinetic energy?