Q: Life itself could not exist without what energy, which plays a vital role in photosynthesis? Read this paragraph and choose the correct option from the provided answers: Our lives are filled with light. Through vision, the most valued of our senses, light can evoke spiritual emotions, such as when we view a magnificent sunset or glimpse a rainbow breaking through the clouds. Light can also simply amuse us in a theater, or warn us to stop at an intersection. It has innumerable uses beyond vision. Light can carry telephone signals through glass fibers or cook a meal in a solar oven. Life itself could not exist without light's energy. From photosynthesis in plants to the sun warming a cold-blooded animal, its supply of energy is vital. Choices: - time energy - spin energy - magnetic energy - light energy A:
light energy

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? Read this paragraph and choose the correct option from the provided answers: 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. Choices: - plasma - sulfate - isotope - reactant A:
reactant

Q: Q: Batteries produce voltage through what type of reaction? Read this paragraph and choose the correct option from the provided answers: Chemical cells are found in batteries. They produce voltage by means of chemical reactions. A chemical cell has two electrodes, which are strips made of different materials, such as zinc and carbon (see Figure below ). The electrodes are suspended in an electrolyte. An electrolyte is a substance containing free ions that can carry electric current. The electrolyte may be either a paste, in which case the cell is called a dry cell, or a liquid, in which case the cell is called a wet cell. Flashlight batteries contain dry cells. Car batteries contain wet cells. Animations at the URL below show how batteries work. Choices: - magnetic - radiation - thermal - chemical A:
A: chemical

Question: Q: Most amphibians breathe with these as larvae? Read this paragraph and choose the correct option from the provided answers: Amphibian skin contains keratin, a protein that is also found in the outer covering of most other four-legged vertebrates. The keratin in amphibians is not too tough to allow gases and water to pass through their skin. Most amphibians breathe with gills as larvae and with lungs as adults. However, extra oxygen is absorbed through the skin. Choices: - nostrils - lungs - pores - gills A:
Answer: gills

*Question*
Q: What scientific word, which gives its name to a type of rock, means "to change form"? Read this paragraph and choose the correct option from the provided answers: Metamorphism. This long word means "to change form. " A rock undergoes metamorphism if it is exposed to extreme heat and pressure within the crust. With metamorphism , the rock does not melt all the way. The rock changes due to heat and pressure. A metamorphic rock may have a new mineral composition and/or texture. Choices: - evaporation - evolution - igneous - metamorphism A:
**Answer**
metamorphism

*Question*
Q: Gibbs free energy values can be used to determine what? Read this paragraph and choose the correct option from the provided answers: Gibbs free energy values can be used to determine equilibrium constants. Choices: - equilibrium differentials - prime constants - equal lines - equilibrium constants A:
**Answer**
equilibrium constants