Ques:Q: Chemical reactions always involve what? Read this paragraph and choose the correct option from the provided answers: Chemical reactions always involve energy. Energy is a property of matter that is defined as the ability to do work. When methane burns, for example, it releases energy in the form of heat and light. Other chemical reactions absorb energy rather than release it. Choices: - fuel - heating - physical change - energy A:

Ans:energy
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Ques:Q: Which types of waves are used for cell phones and radar? Read this paragraph and choose the correct option from the provided answers: Microwaves are used for cell phones and radar. Choices: - light waves - thermal waves - sound waves - microwaves A:

Ans:microwaves
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Ques:Q: An enzyme is an organic catalyst produced by what? Read this paragraph and choose the correct option from the provided answers: An enzyme is an organic catalyst produced by a living cell. Enzymes are such powerful catalysts that the reactions they promote occur rapidly at body temperature. Without the help of enzymes, these reactions would require high temperatures and long reaction times. The molecule or molecules on which an enzyme acts are called its substrates. An enzyme has an active site where its substrate or substrates bind to form an enzymesubstrate complex. The reaction occurs, and product is released:. Choices: - DNA - the liver - amino acid - living cell A:

Ans:living cell
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Ques:Q: Vectors along the same line can be what to one another like ordinary numbers? Read this paragraph and choose the correct option from the provided answers: Components along the same axis, say the x-axis, are vectors along the same line and, thus, can be added to one another like ordinary numbers. The same is true for components along the y-axis. (For example, a 9-block eastward walk could be taken in two legs, the first 3 blocks east and the second 6 blocks east, for a total of 9, because they are along the same direction. ) So resolving vectors into components along common axes makes it easier to add them. Now that the components of R are known, its magnitude and direction can be found. Step 3. To get the magnitude. Choices: - noted - taken - lost - added A:

Ans:
added
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