Nursing Elites

1. Which mineral is essential for muscle function and nerve transmission?

• A. Calcium
• B. Iron
• C. Sodium
• D. Potassium

Correct answer: D

Rationale: Potassium is the correct answer as it is essential for muscle function and nerve transmission. Potassium plays a crucial role in regulating muscle contractions, including the heart's beating, and is vital for transmitting electrical signals within the nervous system. Calcium (Choice A) is important for muscle contraction but is not the primary mineral for nerve transmission. Iron (Choice B) is important for oxygen transport in the blood. Sodium (Choice C) is important for fluid balance but is not primarily responsible for muscle function and nerve transmission.

2. Which type of waves do not require a medium for propagation?

• A. Transverse waves
• B. Longitudinal waves
• C. Electromagnetic waves
• D. Surface waves

Correct answer: C

Rationale: Electromagnetic waves do not require a medium for propagation as they consist of oscillating electric and magnetic fields that can travel through a vacuum. This property allows electromagnetic waves, such as light, radio waves, and X-rays, to propagate through space. In contrast, transverse and longitudinal waves require a medium (solid, liquid, or gas) for propagation. Transverse waves have vibrations perpendicular to the direction of energy transfer, while longitudinal waves have vibrations parallel to the direction of energy transfer. Surface waves, which are a combination of transverse and longitudinal waves, also need a medium for propagation. Understanding the distinction between these wave types is essential in various fields, including physics and communication technologies.

3. Which hormone, produced by the thyroid gland, regulates calcium levels in the blood by enhancing calcium absorption in the intestines and reducing calcium loss in the kidneys?

• A. Calcitonin
• B. Parathyroid hormone (PTH)
• C. Thyroxine
• D. Insulin

Correct answer: A

Rationale: Calcitonin is the hormone produced by the thyroid gland that regulates calcium levels in the blood. It enhances calcium absorption in the intestines and reduces calcium loss in the kidneys. Parathyroid hormone (PTH) operates oppositely to calcitonin by increasing calcium levels in the blood. Thyroxine is a thyroid gland hormone that primarily regulates metabolism, not calcium levels. Insulin, produced by the pancreas, is responsible for controlling blood sugar levels, not calcium levels. Therefore, the correct answer is Calcitonin as it specifically targets calcium regulation in the body.

4. What property of matter determines its resistance to changes in shape or size?

• A. Solid
• B. Liquid
• C. Gas
• D. Plasma

Correct answer: A

Rationale: The correct answer is 'Solid.' Solids have a definite shape and volume, providing them with a strong resistance to changes in shape or size. Liquids and gases do not have a definite shape, making them prone to changing shape or size easily. Plasmas, on the other hand, are ionized gases with high energy levels and lack a definite shape or volume, which does not contribute to resistance against changes in shape or size. Therefore, the properties of solids make them best suited for resisting changes in shape or size compared to liquids, gases, and plasmas.

5. 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.

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