CHEM 1011 Exam 3 Questions With Complete Solutions

CHEM 1011 Exam 3 Questions With Complete Solutions The graph to the right shows measurements of atmospheric CO₂ concentration measured of at the Mauna Loa observatory on the island of Hawaii. The inset shows the typical change in atmospheric CO₂ concentration over a calendar year. What is the primary cause of the seasonal variation? A.Increasing anthropogenic emissions of CO₂ during the winter in the northern hemisphere B.uncertainties in the measured data ("noise") C.Seasonal changes in photosynthesis and respiration by plants D.Scientists do not yet understand this seasonal variation correct answer: C.Seasonal changes in photosynthesis and respiration by plants Which best describes the greenhouse effect? A. Radiation emitted from the sun is absorbed by the atmosphere B. Radiation emitted from the surface of the earth is emitted directly to space C. Radiation emitted from the surface of the earth is absorbed by the atmosphere D. Radiation emitted from the sun is absorbed by the earth's surface correct answer: C. Radiation emitted from the surface of the earth is absorbed by the atmosphere An atom of which of the following elements has the greatest ability to attract electrons? Use the periodic table and your knowledge of the relevant periodic trend. A. chlorine B. iodine C. carbon D. lithium correct answer: A. chlorine Which compound or molecule contains polar, covalent bonds? A. F₂ B. NaF C. He D. CF₄ correct answer: D. CF₄ Which is a polar molecule? A. CH₄