Nursing Elites

1. What is the molarity of a solution made by dissolving 4.0 grams of NaCl into enough water to make 120 mL of solution? The atomic mass of Na is 23.0 g/mol, and Cl is 35.5 g/mol.

• A. 0.34 M
• B. 0.57 M
• C. 0.034 M
• D. 0.057 M

Correct answer: B

Rationale: To find the molarity, first calculate the moles of NaCl. Moles of NaCl = 4.0 g / (23.0 g/mol + 35.5 g/mol) = 0.068 mol. Next, use the formula for molarity: Molarity = moles of solute / liters of solution. Molarity = 0.068 mol / 0.120 L = 0.57 M. Therefore, the molarity of the solution is 0.57 M. Choice A, 0.34 M, is incorrect as it does not match the calculated molarity. Choice C, 0.034 M, is incorrect as it is a decimal point off from the correct molarity. Choice D, 0.057 M, is incorrect as it does not match the calculated molarity of 0.57 M.

2. What does half-life refer to?

• A. Radioactive intensity to completely disappear
• B. The number of neutrons in a nucleus to double
• C. The number of protons in a nucleus to change
• D. An isotope to decay by half of its initial quantity

Correct answer: D

Rationale: Half-life refers to the time it takes for half of the radioactive atoms in a sample to decay. This means that after one half-life, half of the initial quantity of the radioactive substance will have decayed. Choice A is incorrect because radioactive intensity doesn't completely disappear during half-life. Choice B is incorrect as half-life doesn't refer to the number of neutrons doubling. Choice C is incorrect as half-life doesn't relate to the number of protons changing.

3. The patella, commonly known as the kneecap, is an example of a:

• A. Sesamoid bone
• B. Long bone
• C. Short bone
• D. Irregular bone

Correct answer: A

Rationale: The patella, also known as the kneecap, is an example of a sesamoid bone. Sesamoid bones develop within tendons, such as the patellar tendon in this case. The patella is embedded in the tendon of the quadriceps muscle, enhancing the mechanical advantage of the muscle and protecting the knee joint. Long bones, like the femur, are characterized by their elongated shape with growth plates at the ends. Short bones, such as those in the wrist and ankle, are cube-shaped bones. Irregular bones, like vertebrae, do not fit into the other bone shape categories due to their unique shapes and functions.

4. Which of the following correctly orders the layers of the epidermis from most superficial to deepest?

• A. S. spinosum, S. basale, S. corneum, S. granulosum, S. lucidum
• B. S. corneum, S. lucidum, S. granulosum, S. spinosum, S. basale
• C. S. corneum, S. spinosum, S. basale, S. granulosum, S. lucidum
• D. S. basale, S. spinosum, S. granulosum, S. lucidum, S. corneum

Correct answer: B

Rationale: The correct order of the layers of the epidermis from most superficial to deepest is: Stratum corneum, Stratum lucidum, Stratum granulosum, Stratum spinosum, Stratum basale. Choice B, 'S. corneum, S. lucidum, S. granulosum, S. spinosum, S. basale,' provides the accurate layering from the outermost to the innermost layer of the epidermis. Choice A is incorrect as it starts with Stratum spinosum, which is not the most superficial layer. Choice C is incorrect as it places Stratum spinosum before Stratum basale. Choice D is incorrect as it starts with Stratum basale, which is the deepest layer of the epidermis.

5. What is the purpose of a catalyst?

• A. To increase a reaction rate by increasing the activation energy
• B. To increase a reaction rate by increasing the temperature
• C. To increase a reaction rate by decreasing the activation energy
• D. To increase a reaction rate by decreasing the temperature

Correct answer: C

Rationale: The purpose of a catalyst is to increase a reaction's rate by decreasing the activation energy required for the reaction to occur. This allows the reaction to proceed more quickly without being consumed in the process. The catalyst provides an alternate mechanism with a lower activation energy, making it easier for the reactants to convert into products. Choice A is incorrect because a catalyst lowers, not increases, the activation energy. Choice B is incorrect because a catalyst does not affect the temperature directly but provides an alternative pathway for the reaction to occur more easily. Choice D is incorrect because a catalyst does not lower the temperature but facilitates the reaction by lowering the activation energy barrier. Therefore, the correct answer is C, 'To increase a reaction rate by decreasing the activation energy.'

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