Nursing Elites

1. Which of the following salt solutions is most likely to conduct electricity well?

• A. A saturated solution
• B. A concentrated solution of a strong electrolyte
• C. A dilute solution of a weak acid
• D. A mixture of a neutral compound and water

Correct answer: B

Rationale: A concentrated solution of a strong electrolyte is most likely to conduct electricity well. Strong electrolytes completely dissociate into ions in solution, allowing for the flow of electric current. This high concentration of ions in the solution enhances its conductivity, making it a better conductor compared to other options. A saturated solution, although containing dissolved ions, may not have a high enough concentration to conduct electricity effectively. A dilute solution of a weak acid is a poor conductor as weak acids only partially dissociate into ions. A mixture of a neutral compound and water does not contain free ions necessary for conducting electricity.

2. Which process involves the body's natural defense against inhaled dust and allergens?

• A. Cellular respiration
• B. Gas exchange
• C. Ciliary action
• D. Bronchoconstriction

Correct answer: C

Rationale: Ciliary action refers to the process where tiny hair-like structures called cilia in the respiratory tract help to sweep away inhaled dust and allergens, preventing them from entering deeper into the lungs. This is a crucial part of the body's natural defense mechanism against respiratory irritants. Cellular respiration (A) is the process where cells use oxygen to produce energy, not a defense mechanism against inhaled particles. Gas exchange (B) involves the exchange of oxygen and carbon dioxide in the lungs, not specifically targeting inhaled dust and allergens. Bronchoconstriction (D) is the narrowing of the airways in response to irritants or allergens, which can lead to breathing difficulties, but it is not the primary defense mechanism against these particles.

3. How does the stability of an atom's nucleus influence its radioactive decay?

• A. Stable nuclei never undergo radioactive decay.
• B. Unstable nuclei are more likely to decay through various processes.
• C. Decay releases energy, making stable nuclei more prone to it.
• D. The element's position on the periodic table determines its decay rate.

Correct answer: B

Rationale: Unstable nuclei are more likely to decay through various processes. The stability of an atom's nucleus is a crucial factor in determining whether it will undergo radioactive decay. Unstable nuclei have an excess of either protons or neutrons, causing an imbalance in the nucleus. To achieve a more stable configuration, these nuclei will undergo radioactive decay by emitting particles or energy. On the contrary, stable nuclei are less likely to undergo radioactive decay as they possess a balanced number of protons and neutrons. Choice A is incorrect because stable nuclei can still undergo radioactive decay, albeit less frequently. Choice C is incorrect as decay does not make stable nuclei more prone to it; rather, it stabilizes them. Choice D is incorrect because an element's decay rate is primarily determined by the nucleus's stability, not its position on the periodic table.

4. Which of the following is the outermost layer of the skin, providing protection against pathogens and the environment?

• A. Dermis
• B. Epidermis
• C. Hypodermis
• D. Stratum corneum (part of the epidermis)

Correct answer: B

Rationale: The epidermis is the correct answer as it is the outermost layer of the skin, providing protection against pathogens and the environment. It consists of multiple layers, including the stratum corneum, which is the outermost layer of the epidermis. The dermis is located beneath the epidermis, offering structural support and housing blood vessels, nerves, and glands. The hypodermis is the deepest layer of the skin, made up of fat and connective tissue that secures the skin to underlying structures. Choice A, Dermis, is incorrect as it is located beneath the epidermis. Choice C, Hypodermis, is incorrect as it is the deepest layer of the skin, not the outermost. Choice D, Stratum corneum (part of the epidermis), is not the correct answer as it is a specific layer within the epidermis and not the overall outermost layer of the skin.

5. What is the role of enzymes in the body?

• A. To transport oxygen
• B. To speed up chemical reactions
• C. To regulate body temperature
• D. To store energy

Correct answer: B

Rationale: Enzymes act as biological catalysts that speed up chemical reactions in the body. They lower the activation energy required for reactions to occur, thus facilitating processes like digestion, metabolism, and other essential functions. Choice A is incorrect as the transportation of oxygen is primarily carried out by red blood cells. Choice C is incorrect as the regulation of body temperature involves mechanisms such as sweating and shivering. Choice D is incorrect as energy storage is mainly performed by molecules like glycogen and triglycerides.

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