Q: What is a representation of the valence electrons of an atom that uses dots around the symbol of the element? Read this paragraph and choose the correct option from the provided answers: In almost all cases, chemical bonds are formed by interactions of valence electrons in atoms. To facilitate our understanding of how valence electrons interact, a simple way of representing those valence electrons would be useful. A Lewis electron dot diagram (or electron dot diagram or a Lewis diagram or a Lewis structure) is a representation of the valence electrons of an atom that uses dots around the symbol of the element. The number of dots equals the number of valence electrons in the atom. These dots are arranged to the right and left and above and below the symbol, with no more than two dots on a side. (It does not matter what order the positions are used. ) For example, the Lewis electron dot diagram for hydrogen is simply. Choices: - watson structure - right structure - time structure - lewis structure A:
lewis structure

Q: In a displacement graph, the slope of the line is the average what? Read this paragraph and choose the correct option from the provided answers: Example 2.17 Determining Average Velocity from a Graph of Displacement versus Time: Jet Car Find the average velocity of the car whose position is graphed in Figure 2.47. Strategy The slope of a graph of x vs. t is average velocity, since slope equals rise over run. In this case, rise = change in displacement and run = change in time, so that. Choices: - direction - speed - time - velocity A:
velocity

Q: Q: What kind of system do echinoderms possess? Read this paragraph and choose the correct option from the provided answers: 15.5 Echinoderms and Chordates Echinoderms are deuterostome marine organisms. This phylum of animals bear a calcareous endoskeleton composed of ossicles covered by a spiny skin. Echinoderms possess a water-based circulatory system. The madreporite is the point of entry and exit for water for the water vascular system. The characteristic features of Chordata are a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail. Chordata contains two clades of invertebrates: Urochordata (tunicates) and Cephalochordata (lancelets), together with the. Choices: - primitive respiratory - autonomic nerous system - photosynthetic - water-based circulatory A:
A: water-based circulatory

Question: Q: What are used to balance chemical equations? Read this paragraph and choose the correct option from the provided answers: Coefficients are used to balance chemical equations. A coefficient is a number placed in front of a chemical symbol or formula. It shows how many atoms or molecules of the substance are involved in the reaction. For example, two molecules of hydrogen would be written as 2H 2 . A coefficient of 1 usually isn't written. Choices: - velocities - densities - fractions - coefficients A:
Answer: coefficients

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Q: Where does most geological activity take place? Read this paragraph and choose the correct option from the provided answers: Most geological activity takes place at plate boundaries. This activity includes volcanoes, earthquakes, and mountain building. The activity occurs as plates interact. Giant slabs of lithosphere moving around can create a lot of activity! The features seen at a plate boundary are determined by the direction of plate motion and by the type of crust found at the boundary. Choices: - plate buildings - plate waves - plate medians - plate boundaries A:
**Answer**
plate boundaries

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Q: What is paleobotany? Read this paragraph and choose the correct option from the provided answers: Paleobotanist How organisms acquired traits that allow them to colonize new environmentsand how the contemporary ecosystem is shapedare fundamental questions of evolution. Paleobotany (the study of extinct plants) addresses these questions through the analysis of fossilized specimens retrieved from field studies, reconstituting the morphology of organisms that disappeared long ago. Paleobotanists trace the evolution of plants by following the modifications in plant morphology: shedding light on the connection between existing plants by identifying common ancestors that display the same traits. This field seeks to find transitional species that bridge gaps in the path to the development of modern organisms. Fossils are formed when organisms are trapped in sediments or environments where their shapes are preserved. Paleobotanists collect fossil specimens in the field and place them in the context of the geological sediments and other fossilized organisms surrounding them. The activity requires great care to preserve the integrity of the delicate fossils and the layers of rock in which they are found. One of the most exciting recent developments in paleobotany is the use of analytical chemistry and molecular biology to study fossils. Preservation of molecular structures requires an environment free of oxygen, since oxidation and degradation of material through the activity of microorganisms depend on its presence. One example of the use of analytical chemistry and molecular biology is the identification of oleanane, a compound that deters pests. Up to this point, oleanane appeared to be unique to flowering plants; however, it has now been recovered from sediments dating from the Permian, much earlier than the current dates given for the appearance of the first flowering plants. Paleobotanists can also study fossil DNA, which can yield a large amount of information, by analyzing and comparing the DNA sequences of extinct plants with those of living and related organisms. Through this analysis, evolutionary... Choices: - study of diseased plants - study of new plants - study of fresh plants - study of extinct plants A:
**Answer**
study of extinct plants