Answer the following question given this paragraph: Normal light microscopes can magnify objects up to about 1,500 times. Electron microscopes can magnify objects up to 1,000,000 times. Why can electron microscopes magnify images so much? A microscope's resolution depends on the wavelength of light used. The smaller the wavelength, the more a microscope can magnify. Light is a wave, and, as such, it has a wavelength associated with it. The wavelength of visible light, which is detected by the eyes, varies from about 700 nm to about 400 nm. One of the startling conclusions about modern science is that electrons also act as waves. However, the wavelength of electrons is much, much shorterabout 0.5 to 1 nm. This allows electron microscopes to magnify 600700 times more than light microscopes. This allows us to see even smaller features in a world that is invisible to the naked eye. Atoms act the way they do because of their structure. We already know that atoms are composed of protons, neutrons, and electrons. Protons and neutrons are located in the nucleus, and electrons orbit around the nucleus. But we need to know the structural details to understand why atoms react the way they do. Virtually everything we know about atoms ultimately comes from light. Before we can understand the composition of atoms (especially electrons), we need to understand the properties of light. Q: While normal light microscopes can magnify objects up to about 1,500 times, what advanced instruments can magnify objects up to 1,000,000 times? Choices: - magnetic microscopes - micro microscopes - electric microscopes - electron microscopes A:
electron microscopes
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Answer the following question given this paragraph: One way mucous membranes protect the body is by producing mucus. Mucus is a sticky, moist secretion that covers mucous membranes. The mucus traps pathogens and particles so they can't enter the body. Q: A sticky, moist secretion that covers mucous membranes is called what? Choices: - sweat - pus - saliva - mucus A:
mucus
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Answer the following question given this paragraph: Mirrors are made from highly reflective metal that is applied to a curved or flat piece of glass. Converging mirrors can be used to focus light headlights, telescopes, satellite TV receivers, and solar cookers all rely on this principle. Q: What are made from highly reflective metal that is applied to a curved or flat piece of glass? Choices: - lenses - kaleidoscopes - prisms - mirrors A:
mirrors
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Answer the following question given this paragraph: 2Al(s) + Fe2O3(s) 2Fe(s) + Al2O3(s) + heat to indicate that heat is one of the products. Chemical equations in which heat is shown as either a reactant or a product are called thermochemical equations. In this reaction, the system consists of aluminum, iron, and oxygen atoms; everything else, including the container, makes up the surroundings. During the reaction, so much heat is produced that the iron liquefies. Eventually, the system cools; the iron solidifies as heat is transferred to the surroundings. A process in which heat (q) is transferred from a system to its surroundings is described as exothermic. By convention, q < 0 for an exothermic reaction. Q: Chemical equations in which heat is shown as either a reactant or a product are called what? Choices: - hydroelectric equations - thorium equations - feedstock equations - thermochemical equations A:
thermochemical equations
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