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

Ex Input:
Passage: 2.2 | Chemical Bonds By the end of this section, you will be able to: • Explain the relationship between molecules and compounds • Distinguish between ions, cations, and anions • Identify the key difference between ionic and covalent bonds • Distinguish between nonpolar and polar covalent bonds • Explain how water molecules link via hydrogen bonds Atoms separated by a great distance cannot link; rather, they must come close enough for the electrons in their valence shells to interact. But do atoms ever actually touch one another? Most physicists would say no, because the negatively charged electrons in their valence shells repel one another. No force within the human body—or anywhere in the natural world—is strong enough to overcome this electrical repulsion. So when you read about atoms linking together or colliding, bear in mind that the atoms are not merging in a physical sense. Instead, atoms link by forming a chemical bond. A bond is a weak or strong electrical attraction that holds atoms in the same vicinity. The new grouping is typically more stable—less likely to react again—than its component atoms were when they were separate. A more or less stable grouping of two or more atoms held together by chemical bonds is called a molecule. The bonded atoms may be of the same element, as in the case of H2, which is called molecular hydrogen or hydrogen gas. When a molecule is made up of two or more atoms of different elements, it is called a chemical compound. Thus, a unit of water, or H2O, is a compound, as is a single molecule of the gas methane, or CH4. Three types of chemical bonds are important in human physiology, because they hold together substances that are used by the body for critical aspects of homeostasis, signaling, and energy production, to name just a few important processes. These are ionic bonds, covalent bonds, and hydrogen bonds. Answer: bonds

Ex Output:
Ionic, covalent, and hydrogen are three important types of what type of interaction between different types of atoms?


Ex Input:
Passage: rates The rates at which reactants are consumed and products are formed during chemical reactions vary greatly. We can identify five factors that affect the rates of chemical reactions: the chemical nature of the reacting substances, the state of subdivision (one large lump versus many small particles) of the reactants, the temperature of the reactants, the concentration of the reactants, and the presence of a catalyst. Answer: catalyst

Ex Output:
The presence of what, which acts as a trigger, affects the rate of chemical reaction?


Ex Input:
Passage: There are three types of mammals, characterized by their method of reproduction. All mammals, except for a few, are viviparous , meaning they produce live young instead of laying eggs. The monotremes , however, have birdlike and reptilian characteristics, such as laying eggs and a cloaca. An example of a monotreme is the platypus with its birdlike beak and egg-laying characteristics. The echidnas are the only other monotreme mammals. A second type of mammal, the marsupial mammal, includes kangaroos, wallabies, koalas and possums. These mammals give birth to underdeveloped embryos, which then climb from the birth canal into a pouch on the front of the mother's body, where it feeds and continues to grow. The remainder of mammals, which is the majority of mammals, are placental mammals. These mammals develop in the mother's uterus, receiving nutrients across the placenta. Placental mammals include humans, rabbits, squirrels, whales, elephants, shrews, and armadillos. Dogs and cats, and sheep, cattle and horses are also placental mammals. Answer: reproduction

Ex Output:

The three types of mammals are characterized by their method of what?


