Answer the following question given this paragraph: Potential energy is energy stored in matter. Q: What is the energy called that is stored in matter? Choices: - stored energy - possible - mechanical - potential A:
potential
Answer the following question given this paragraph: Sulfuric acid is produced in extremely large quantities in the United States (about 40 million tons/year). This material is manufactured by oxidizing sulfur to form sulfur trioxide. The SO 3 is then dissolved in water to form the sulfuric acid. Most of the sulfuric acid produced is used in fertilizers. This acid is also found in lead-acid car batteries. Q: What is sulfur trioxide dissolved in to form sulfuric acid? Choices: - silver - mercury - lead - water A:
water
Q: Answer the following question given this paragraph: Electron Shells and the Bohr Model It should be stressed that there is a connection between the number of protons in an element, the atomic number that distinguishes one element from another, and the number of electrons it has. In all electrically neutral atoms, the number of electrons is the same as the number of protons. Thus, each element, at least when electrically neutral, has a characteristic number of electrons equal to its atomic number. An early model of the atom was developed in 1913 by Danish scientist Niels Bohr (18851962). The Bohr model shows the atom as a central nucleus containing protons and neutrons, with the electrons in circular orbitals at specific distances from the nucleus, as illustrated in Figure 2.6. These orbits form electron shells or energy levels, which are a way of visualizing the number of electrons in the outermost shells. These energy levels are designated by a number and the symbol "n. " For example, 1n represents the first energy level located closest to the nucleus. Q: What is the number of electrons equal to in every electrically neutral atom? Choices: - Electrons - molecules - nucleus - protons A:
A: protons
Question: Answer the following question given this paragraph: Group 7 (Mn, Tc, and Re) Continuing across the periodic table, we encounter the group 7 elements (Table 23.5 "Some Properties of the Elements of Groups 6 and 7"). One group 7 metal (Mn) is usually combined with iron in an alloy called ferromanganese, which has been used since 1856 to improve the mechanical properties of steel by scavenging sulfur and oxygen impurities to form MnS and MnO. Technetium is named after the Greektechnikos, meaning "artificial," because all its isotopes are radioactive. One isotope, 99mTc (m for metastable), has become an important biomedical tool for imaging internal organs. (For more information on biomedical imaging, see Chapter 20 "Nuclear Chemistry", Section 20.5 "Applied Nuclear Chemistry". ) Because of its scarcity, Re is one of the most expensive elements, and its applications are limited. It is, however, used in a bimetallic Pt/Re catalyst for refining high-octane gasoline. All three group 7 elements have seven valence electrons and can form compounds in the +7 oxidation state. Once again, the lightest element exhibits multiple oxidation states. Compounds of Mn in oxidation states ranging from 3 to +7 are known, with the most common being +2 and +4 (Figure 23.5 "Compounds of Manganese in Oxidation States +2 to +7"). In contrast, compounds of Tc and Re in the +2 oxidation state are quite rare. Because the electronegativity of Mn is anomalously low, elemental manganese is unusually reactive. In contrast, the chemistry of Tc is similar to that of Re because of their similar size and electronegativity, again a result of the lanthanide contraction. Due to the stability of the half-filled 3d5 electron configuration, the aqueous Mn3+ ion, with a 3d4 valence electron configuration, is a potent oxidant that is able to oxidize water. It is difficult to generalize about other oxidation states for Tc and Re because their stability depends dramatically on the nature of the compound. Consistent with higher oxidation states being more stable for the heavier transition metals, reacting Mn... Q: Technetium is named after the greektechnikos, meaning "artificial," because all its isotopes are what? Choices: - rare - plastic - neutral - radioactive A:
Answer: radioactive
*Question*
Answer the following question given this paragraph: Hydrates Many ionic compounds occur as hydrates, compounds that contain specific ratios of loosely bound water molecules, called waters of hydration. Waters of hydration can often be removed simply by heating. For example, calcium dihydrogen phosphate can form a solid that contains one molecule of water per Ca(H2PO4)2 unit and is used as a leavening agent in the food industry to cause baked goods to rise. The empirical formula for the solid is Ca(H 2PO4)2H2O. In contrast, copper sulfate usually forms a blue solid that contains five waters of hydration per formula unit, with the empirical formula CuSO 45H2O. When heated, all five water molecules are lost, giving a white solid with the empirical formula CuSO 4 (Figure 2.9 "Loss of Water from a Hydrate with Heating"). Q: Many ionic compounds occur as hydrates, compounds that contain specific ratios of loosely bound water molecules, called waters of hydration. waters of hydration can often be removed simply by doing this? Choices: - cooling - observing - melting - heating A:
**Answer**
heating
*Question*
Answer the following question given this paragraph: Q: What is above each leaf scar? Choices: - chambered pitch - lenticel - stipule scar - an axillary bud A:
**Answer**
an axillary bud