Answer the following question given this paragraph: A whole molecule may also have a separation of charge, depending on its molecular structure and the polarity of each of its bonds. If such a charge separation exists, the molecule is said to be a polar molecule (or dipole); otherwise the molecule is said to be nonpolar. The dipole moment measures the extent of net charge separation in the molecule as a whole. We determine the dipole moment by adding the bond moments in three-dimensional space, taking into account the molecular structure. For diatomic molecules, there is only one bond, so its bond dipole moment determines the molecular polarity. Homonuclear diatomic molecules such as Br2 and N2 have no difference in electronegativity, so their dipole moment is zero. For heteronuclear molecules such as CO, there is a small dipole moment. For HF, there is a larger dipole moment because there is a larger difference in electronegativity. When a molecule contains more than one bond, the geometry must be taken into account. If the bonds in a molecule are arranged such that their bond moments cancel (vector sum equals zero), then the molecule is nonpolar. This is the situation in CO2 (Figure 7.27). Each of the bonds is polar, but the molecule as a whole is nonpolar. From the Lewis structure, and using VSEPR theory, we determine that the CO2 molecule is linear with polar C=O bonds on opposite sides of the carbon atom. The bond moments cancel because they are pointed in opposite directions. In the case of the water molecule (Figure 7.27), the Lewis structure again shows that there are two bonds to a central atom, and the electronegativity difference again shows that each of these bonds has a nonzero bond moment. In this case, however,. Q: Why do homonuclear diatomic molecules have zero dipole moment? Choices: - no electrical attraction - no activation energy - at homeostasis - no difference in electronegativity A:
no difference in electronegativity
Answer the following question given this paragraph: Sphenodontia Sphenodontia ("wedge tooth") arose in the Mesozoic era and includes only one living genus, Tuatara, comprising two species that are found in New Zealand (Figure 29.26). Tuataras measure up to 80 centimeters and weigh about 1 kilogram. Although quite lizard-like in gross appearance, several unique features of the skull and jaws clearly define them and distinguish the group from the squamates. Q: Sphenodontia sphenodontia ("wedge tooth") arose in the mesozoic era and includes only one of what? Choices: - outside genus - traveling genus - inner genus - living genus A:
living genus
Q: Answer the following question given this paragraph: The spiral structure in the picture is a large organic molecule. Can you guess what it is? Here's a hint: molecules like this one determine who you are. They contain genetic information that controls your characteristics. They determine your eye color, facial features, and other physical attributes. What molecule is it?. Q: What is the distinctive shape of the molecule that contains genetic information? Choices: - cube - conical - cylindrical - spiral A:
A: spiral
Question: Answer the following question given this paragraph: Secondary succession occurs in a formerly inhabited area that was disturbed. Soil is already in place, so pioneer species include small plants such as grasses. Q: What occurs in a formerly inhabited area that was disturbed? Choices: - spontaneous mutation - mass extinction - natural selection - secondary succession A:
Answer: secondary succession
*Question*
Answer the following question given this paragraph: Physics is the study of energy, matter, and their interactions. It is concerned with matter and energy at all levelsfrom the most fundamental particles of matter to the entire universe. Q: Which branch of science is the study of energy, matter, and their interactions? Choices: - geology - biology - meteorology - physics A:
**Answer**
physics
Q: Answer the following question given this paragraph: Cells also divide in order to replace damaged or worn-out cells. Q: What do cells do in order to replace damaged or worn out cells? Choices: - replicate - die - fold - divide A:
A: divide