Nursing Elites

1. Which of the following best defines the term amphoteric?

• A. A substance that conducts electricity due to ionization when dissolved in a solvent
• B. A substance that can act as an acid or a base depending on the properties of the solute
• C. A substance that, according to the Brønsted-Lowry Acid-Base Theory, is a proton-donor
• D. A substance that donates its proton and forms its conjugate base in a neutralization reaction

Correct answer: B

Rationale: An amphoteric substance can act as both an acid or a base depending on the environment. It can donate a proton (act as an acid) or accept a proton (act as a base), showing versatility in its behavior. Choice A is incorrect as it describes an electrolyte rather than an amphoteric substance. Choice C is incorrect as it defines an acid based on the Brønsted-Lowry Acid-Base Theory. Choice D is incorrect as it specifically refers to a substance donating a proton in a neutralization reaction, not capturing the dual behavior of an amphoteric substance.

2. In a single displacement reaction, one element takes the place of another element in a compound. Which of the following is an example?

• A. 2H2 + O2 -> 2H2O
• B. Zn + 2HCl -> ZnCl2 + H2
• C. CaCO3 -> CaO + CO2
• D. CH4 + 2O2 -> CO2 + 2H2O

Correct answer: B

Rationale: Option B demonstrates a single displacement reaction where zinc (Zn) displaces hydrogen (H) in hydrochloric acid (HCl) to produce zinc chloride (ZnCl2) and hydrogen gas (H2). This reaction exemplifies the concept of one element (Zn) replacing another element (H) in a compound (HCl), which is characteristic of single displacement reactions. Choices A, C, and D do not involve a single element displacing another in a compound, making them incorrect. In choice A, hydrogen and oxygen combine to form water, which is not a single displacement reaction. In choice C, calcium carbonate decomposes into calcium oxide and carbon dioxide, not involving displacement of elements. In choice D, methane reacts with oxygen to form carbon dioxide and water, which is a combustion reaction, not a single displacement reaction.

3. What is any number raised to the power of zero?

• A. One
• B. Itself
• C. Zero
• D. Two

Correct answer: A

Rationale: The correct answer is A: One. Any number raised to the power of zero is always equal to 1. This is a fundamental property of exponentiation. Choice B, 'Itself,' is vague and does not specify a numerical value. Choice C, 'Zero,' is incorrect as any nonzero number raised to the power of zero is 1, not 0. Choice D, 'Two,' is incorrect as any number raised to the power of zero is 1, not 2.

4. The acceleration of a falling object due to gravity has been proven to be 9.8 m/s². A scientist drops a cactus four times and measures the acceleration with an accelerometer and gets the following results: 9.79 m/s², 9.81 m/s², 9.80 m/s², and 9.78 m/s². Which of the following accurately describes the measurements?

• A. They're both accurate and precise.
• B. They're accurate but not precise.
• C. They're precise but not accurate.
• D. They're neither accurate nor precise.

Correct answer: A

Rationale: The measurements are both close to the actual value (accurate) and consistent with each other (precise). Accuracy refers to how close a measurement is to the true value, and precision refers to the reproducibility or consistency of the measurements. In this case, the measured values are all very close to the actual value of 9.8 m/s², indicating accuracy. Additionally, the measurements are clustered closely together, demonstrating precision. Therefore, the measurements are both accurate and precise, making choice A the correct answer. Choices B, C, and D are incorrect because the measurements exhibit both accuracy and precision, as they are close to the true value and also consistent with each other.

5. What is the waste product of protein digestion?

• A. Glucose
• B. Amino acids
• C. Fatty acids
• D. Ammonia

Correct answer: D

Rationale: The waste product of protein digestion is ammonia. Protein digestion breaks down proteins into amino acids, and during this process, ammonia is produced. Ammonia is toxic and needs to be converted into urea in the liver for excretion via urine. Glucose is a product of carbohydrate digestion, amino acids are building blocks of proteins, and fatty acids are the end products of fat digestion. Therefore, the correct answer is ammonia.

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