Answer the following question given this paragraph: Technically, any redox reaction can be set up to make a voltaic cell. In modern society, however, only certain redox reactions are put to practical use. A portable voltaic cell that generates electricity to power devices for our convenience is called a battery. All batteries are based on redox reactions. The first battery (called a "voltaic pile") was constructed by the Italian scientist Alessandro Volta in 1800 and was based on the copper/zinc reaction depicted in - ball-ch14_s03_f01. Unfortunately, it was messy, requiring quantities of copper and zinc salts dissolved in water. In 1866, the French scientist Georges Leclanche invented the dry cell, a precursor to today's modern battery. A schematic of a dry cell is shown in - ball-ch14_s03_f02. The zinc case and the central carbon rod serve as the anode and cathode, respectively. The other reactants are combined into a moist paste that minimizes free liquid, so the battery is less messy (hence the name dry cell). The actual redox reaction is complex but can be represented by the following redox reaction: + 2+ Zn + 2MnO2 + 2NH4 Zn + Mn2O3 + 2NH3 + H2O A dry cell has a voltage of about 1.56 V. While common and useful, dry cells have relatively short lifetimes and contain acidic components. They also cannot be recharged, so they are one-use only. Batteries that can be used only once are calledprimary batteries. Figure 14.2 Dry Cells. Q: Technically, any redox reaction can be set up to make a what? Choices: - Black Cell - blocky cell - skaht cell - voltaic cell A:
voltaic cell

Answer the following question given this paragraph: 22.6 The Hall Effect We have seen effects of a magnetic field on free-moving charges. The magnetic field also affects charges moving in a conductor. One result is the Hall effect, which has important implications and applications. Figure 22.27 shows what happens to charges moving through a conductor in a magnetic field. The field is perpendicular to the electron drift velocity and to the width of the conductor. Note that conventional current is to the right in both parts of the figure. In part (a), electrons carry the current and move to the left. In part (b), positive charges carry the current and move to the right. Moving electrons feel a magnetic force toward one side of the conductor, leaving a net positive charge on the other side. This separation of charge creates a voltage , known as the Hall emf, across the conductor. The creation of a voltage across a current-carrying conductor by a magnetic field is known as the Hall effect, after Edwin Hall, the American physicist who discovered it in 1879. Q: The creation of a voltage across a current-carrying conductor by a magnetic field is known as what? Choices: - off effect - newton effect - show effect - hall effect A:
hall effect

Answer the following question given this paragraph: Radioactive elements and isotopes have unstable nuclei. To become more stable, the nuclei undergo radioactive decay. In radioactive decay, the nuclei give off, or emit, radiation in the form of energy and often particles as well. There are several types of radioactive decay, including alpha, beta, and gamma decay. Energy is emitted in all three types of decay, but only alpha and beta decay also emit particles. Q: Radioactive decay can give off energy and what else? Choices: - light - ions - atoms - particles A:
particles

Answer the following question given this paragraph: 24.4 | Fungal Parasites and Pathogens By the end of this section, you will be able to: Describe fungal parasites and pathogens of plants Describe the different types of fungal infections in humans Explain why antifungal therapy is hampered by the similarity between fungal and animal cells Parasitism describes a symbiotic relationship in which one member of the association benefits at the expense of the other. Both parasites and pathogens harm the host; however, the pathogen causes a disease, whereas the parasite usually does not. Commensalism occurs when one member benefits without affecting the other. Q: What type of relationship occurs between organisms when one member benefits without affecting the other? Choices: - cooperative - bilateral - parasitic - commensalism A:
commensalism