Answer the following question given this paragraph: Summary 12.1 Chemical Reaction Rates The rate of a reaction can be expressed either in terms of the decrease in the amount of a reactant or the increase in the amount of a product per unit time. Relations between different rate expressions for a given reaction are derived directly from the stoichiometric coefficients of the equation representing the reaction. 12.2 Factors Affecting Reaction Rates The rate of a chemical reaction is affected by several parameters. Reactions involving two phases proceed more rapidly when there is greater surface area contact. If temperature or reactant concentration is increased, the rate of a given reaction generally increases as well. A catalyst can increase the rate of a reaction by providing an alternative pathway that causes the activation energy of the reaction to decrease. 12.3 Rate Laws Rate laws provide a mathematical description of how changes in the amount of a substance affect the rate of a chemical reaction. Rate laws are determined experimentally and cannot be predicted by reaction stoichiometry. The order of reaction describes how much a change in the amount of each substance affects the overall rate, and the overall order of a reaction is the sum of the orders for each substance present in the reaction. Reaction orders are typically first order, second order, or zero order, but fractional and even negative orders are possible. 12.4 Integrated Rate Laws Differential rate laws can be determined by the method of initial rates or other methods. We measure values for the initial rates of a reaction at different concentrations of the reactants. From these measurements, we determine the order of the reaction in each reactant. Integrated rate laws are determined by integration of the corresponding differential. Q: The rate of a reaction can be expressed either in terms of the decrease in the amount of what or the increase in the amount of a product per unit time? Choices: - plasma - sulfate - isotope - reactant A:
reactant
(Question)
Answer the following question given this paragraph: The electrode at which reduction occurs is called the cathode . The cathode gradually increases in mass because of the production of copper metal. The concentration of copper(II) ions in the half-cell solution decreases. The cathode is the positive electrode. Q: What is the electrode at which reduction occurs called? Choices: - reducthode - anode - cathine - cathode A:
(Answer)
cathode
Ques: Answer the following question given this paragraph: A machine is any device that makes work easier by changing a force. Work is done whenever a force moves an object over a distance. The amount of work done is represented by the equation:. Q: What do you call any device that makes work easier by changing a force? Choices: - technology - invention - battery - machine A:
Ans: machine
(Q).
Answer the following question given this paragraph: Q: In the case of the thyroid hormone pathway, thyroid hormone itself carries out what kind of feedback? Choices: - positive - continued - effective - negative A:
(A).
negative
Ques:Answer the following question given this paragraph: Although renewable, soil takes a very long time to formup to hundreds of millions of years. So, for human purposes, soil is a nonrenewable resource. It is also constantly depleted of nutrients through careless use, and eroded by wind and water. For example, misuse of soil caused a huge amount of it to simply blow away in the 1930s during the Dust Bowl (see Figure below ). Soil must be used wisely to preserve it for the future. Conservation practices include contour plowing and terracing. Both reduce soil erosion. Soil also must be protected from toxic wastes. Q: What kind of a resource is soil, for human purposes? Choices: - renewable resource - guarana resource - emanates resource - nonrenewable resource A:

Ans:nonrenewable resource
Answer the following question given this paragraph: The theory of plate tectonics explains most of the features of Earth's surface. Plate tectonics helps us to understand where and why mountains form. Using the theory, we know where new ocean floor will be created and where it will be destroyed. We know why earthquakes and volcanic eruptions happen where they do. We even can search for mineral resources using information about past plate motions. Plate tectonics is the key that unlocks many of the mysteries of our amazing planet. Q: What theory explains most of the features of earth's surface? Choices: - Big Bang theory - flat earth theory - string theory - plate tectonics A:
plate tectonics