Answer the following question given this paragraph: The ozone in smog is also harmful to human health. The image below shows the levels of ozone to watch out for ( Figure below ). Some people are especially sensitive to ozone. They can be harmed by levels of ozone that would not affect most other people. These people include those with lung or heart problems. Q: What harmful light does ozone reduce in the upper atmospheres? Choices: - infrared light - visible light - specific light - ultraviolet light A:
ultraviolet light
Answer the following question given this paragraph: A chemical reaction is usually written in a way that suggests it proceeds in one direction, the direction in which we read, but all chemical reactions are reversible, and both the forward and reverse reaction occur to one degree or another depending on conditions. In a chemical equilibrium, the forward and reverse reactions occur at equal rates, and the concentrations of products and reactants remain constant. If we run a reaction in a closed system so that the products cannot escape, we often find the reaction does not give a 100% yield of products. Instead, some reactants remain after the concentrations stop changing. At this point, when there is no further change in concentrations of reactants and products, we say the reaction is at equilibrium. A mixture of reactants and products is found at equilibrium. For example, when we place a sample of dinitrogen tetroxide (N2O4, a colorless gas) in a glass tube, it forms nitrogen dioxide (NO2, a brown gas) by the reaction N 2 O 4(g) 2NO 2(g) The color becomes darker as N2O4 is converted to NO2. When the system reaches equilibrium, both N2O4 and NO2 are present (Figure 13.2). Q: Chemical reactions are typically written to imply that they proceed in one direction - if they can occur in either direction, they are considered what? Choices: - singular - observable - reactive - reversible A:
reversible
Q: Answer the following question given this paragraph: Introduction Virtually every task performed by living organisms requires energy. Energy is needed to perform heavy labor and exercise, but humans also use a great deal of energy while thinking, and even during sleep. In fact, the living cells of every organism constantly use energy. Nutrients and other molecules are imported, metabolized (broken down) and possibly synthesized into new molecules, modified if needed, transported around the cell, and may be distributed to the entire organism. For example, the large proteins that make up muscles are actively built from smaller molecules. Complex carbohydrates are broken down into simple sugars that the cell uses for energy. Just as energy is required to both build and demolish a building, energy is required for both the synthesis and breakdown of molecules. Additionally, signaling molecules such as hormones and neurotransmitters are transported between cells. Pathogenic bacteria and viruses are ingested and broken down by cells. Cells must also export waste and toxins to stay healthy, and many cells must swim or move surrounding materials via the beating motion of cellular appendages like cilia and flagella. The cellular processes listed above require a steady supply of energy. From where, and in what form, does this energy come? How do living cells obtain energy, and how do they use it? This chapter will discuss different forms of energy and the physical laws that govern energy transfer. This chapter will also describe how cells use energy and replenish it, and how chemical reactions in the cell are performed with great efficiency. Q: What is required for both the synthesis and breakdown of molecules? Choices: - sunlight - mixing - heating - energy A:
A: energy
Question: Answer the following question given this paragraph: There is a one problem when using food chains to accurately describe most ecosystems. Even when all organisms are grouped into appropriate trophic levels, some of these organisms can feed on species from more than one trophic level; likewise, some of these organisms can be eaten by species from multiple trophic levels. In other words, the linear model of ecosystems, the food chain, is not completely descriptive of ecosystem structure. A holistic modelwhich accounts for all the interactions between different species and their complex interconnected relationships with each other and with the environmentis a more accurate and descriptive model for ecosystems. A food web is a graphic representation of a holistic, non-linear web of primary producers, primary consumers, and higher-level consumers used to describe ecosystem structure and dynamics (Figure 46.6). Q: A problem with using food chains to describe ecosystems is that some organisms can feed on or be consumed by species from more than one of what level? Choices: - biome level - habitat level - pH level - trophic level A:
Answer: trophic level
*Question*
Answer the following question given this paragraph: helium-3 is produced by beta decay of a certain nuclide. Q: Helium-3 is produced by beta decay of a certain what? Choices: - electron - quark - particle - nuclide A:
**Answer**
nuclide
(Question)
Answer the following question given this paragraph: Energy that the sun and other stars release into space is called electromagnetic energy . This form of energy travels through space as electrical and magnetic waves. Electromagnetic energy is commonly called light. It includes visible light, as well as radio waves, microwaves, and X rays ( Figure below ). Q: Energy that the sun and other stars release into space is called what? Choices: - static energy - kinetic energy - mechanical energy - electromagnetic energy A:
(Answer)
electromagnetic energy