Nursing Elites

1. What is the balanced chemical equation for the reaction between sodium and chlorine to form sodium chloride?

• A. Na + Cl2 -> NaCl
• B. 2Na + Cl2 -> 2NaCl
• C. Na2 + Cl -> 2NaCl
• D. Na + 2Cl -> NaCl2

Correct answer: B

Rationale: In a balanced chemical equation, the number of atoms of each element must be the same on both sides of the equation. When sodium (Na) reacts with chlorine (Cl2) to form sodium chloride (NaCl), we need to ensure the equation is balanced. There are 2 chlorine atoms in Cl2; hence, we need 2 sodium atoms on the left side to balance it. Therefore, the balanced chemical equation is 2Na + Cl2 -> 2NaCl. Choice A is incorrect because it does not have the correct coefficients to balance the equation. Choice C is incorrect as it incorrectly represents the formula of sodium. Choice D is incorrect as it forms NaCl2, which is not the correct compound formed in this reaction.

2. What is the term for the number of moles of solute per liter of solution?

• A. Molarity
• B. Molality
• C. Normality
• D. Concentration

Correct answer: A

Rationale: Molarity is the correct term for the number of moles of solute per liter of solution. It is expressed as moles of solute divided by liters of solution. Molality (B) is similar but is moles of solute per kilogram of solvent. Normality (C) is the number of equivalents of solute per liter of solution, and Concentration (D) is a general term for the amount of solute present in a given quantity of solution. Therefore, the correct answer is A, molarity, as it specifically refers to moles of solute per liter of solution.

3. Nuclear fusion powers the sun and other stars. What is the main obstacle to achieving controlled nuclear fusion on Earth for energy production?

• A. Lack of suitable materials to handle high temperatures and pressures.
• B. Limited availability of fusion fuels like deuterium and tritium.
• C. Difficulty in containing the plasma where fusion occurs.
• D. All of the above

Correct answer: D

Rationale: The main obstacle to achieving controlled nuclear fusion on Earth for energy production involves a combination of factors. A) Lack of suitable materials to handle high temperatures and pressures is a significant challenge due to the extreme conditions required for fusion reactions. B) Limited availability of fusion fuels like deuterium and tritium can pose a constraint on the scalability and sustainability of fusion energy. C) Difficulty in containing the plasma where fusion occurs is another critical issue as plasma instabilities and heat losses can hinder the efficiency of fusion reactions. Therefore, all of the options (A, B, and C) contribute to the challenges in achieving controlled nuclear fusion for energy production on Earth.

4. What is the main function of calcitonin, a hormone produced by the thyroid gland?

• A. Stimulate metabolism and heat production
• B. Increase calcium absorption from the intestines
• C. Enhance bone growth and development
• D. Lower blood calcium levels

Correct answer: D

Rationale: Calcitonin is a hormone produced by the thyroid gland that primarily functions to lower blood calcium levels. It achieves this by inhibiting bone breakdown and promoting calcium excretion by the kidneys. Therefore, the correct answer is D as it reflects the main role of calcitonin in calcium homeostasis. Choices A, B, and C are incorrect as they do not align with the primary function of calcitonin. Calcitonin does not stimulate metabolism and heat production (Choice A), increase calcium absorption from the intestines (Choice B), or enhance bone growth and development (Choice C).

5. Which layer of the skin is responsible for new skin cell production?

• A. Stratum corneum
• B. Stratum basale
• C. Stratum granulosum
• D. Stratum spinosum

Correct answer: B

Rationale: The correct answer is B, Stratum basale. The stratum basale, also known as the basal layer or stratum germinativum, is the deepest layer of the epidermis and is responsible for new skin cell production through cell division. It contains basal cells that continuously divide to produce new keratinocytes, which move up through the layers of the epidermis. Choice A, Stratum corneum, is the outermost layer of the epidermis consisting of dead cells filled with keratin. It serves a protective function but is not involved in new skin cell production. Choice C, Stratum granulosum, is a layer of the epidermis where keratinocytes undergo changes in their structure and composition. It is involved in the process of keratinization but not in new skin cell production. Choice D, Stratum spinosum, is a layer of the epidermis where cells become interconnected by desmosomes. While it plays a role in providing strength and support to the epidermis, it is not primarily responsible for new skin cell production.

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