Nursing Elites

1. Salts like sodium iodide (NaI) and potassium chloride (KCl) use what type of bond?

• A. Ionic bonds
• B. Disulfide bridges
• C. Covalent bonds
• D. London dispersion forces

Correct answer: A

Rationale: Salts like sodium iodide (NaI) and potassium chloride (KCl) use ionic bonds. Ionic bonds are formed between atoms with significantly different electronegativities, leading to the transfer of electrons from one atom to another. In the case of NaI and KCl, sodium (Na) and potassium (K) are metals that easily lose electrons to become positively charged ions, while iodide (I) and chloride (Cl) are nonmetals that readily accept electrons to become negatively charged ions. The attraction between the oppositely charged ions forms the ionic bond, which holds the compound together in a lattice structure. Disulfide bridges (option B) are covalent bonds formed between sulfur atoms in proteins, not in salts. Covalent bonds (option C) involve the sharing of electrons between atoms and are typically seen in molecules, not ionic compounds like salts. London dispersion forces (option D) are weak intermolecular forces that occur between all types of molecules but are not the primary type of bond in salts like NaI and KCl.

2. Which of the following statements is NOT true of most metals?

• A. Most of them are good conductors of heat.
• B. Most of them are gases at room temperature.
• C. Most of them are ductile.
• D. They make up the majority of elements on the periodic table.

Correct answer: B

Rationale: The correct answer is B because most metals are not gases at room temperature; they are usually solid and good conductors of heat. Metals are generally known for being good conductors of heat, ductile, and making up the majority of elements on the periodic table. Choice A is correct as metals, in general, are good conductors of heat. Choice C is also correct as most metals exhibit ductility. Choice D is correct as metals constitute the majority of elements found on the periodic table.

3. What is the role of surfactant in the respiratory system?

• A. To trap dust particles
• B. To increase lung compliance
• C. To produce mucus
• D. To generate oxygen during respiration

Correct answer: B

Rationale: The correct answer is B: To increase lung compliance. Surfactant is a substance produced by type II alveolar cells in the lungs that reduces surface tension in the alveoli. This reduction in surface tension helps to increase lung compliance, making it easier for the lungs to expand and contract during breathing. Improved lung compliance is essential for efficient gas exchange in the respiratory system, facilitating oxygen uptake and carbon dioxide removal. Choices A, C, and D are incorrect because surfactant does not trap dust particles, produce mucus, or generate oxygen during respiration. Instead, its primary function lies in reducing surface tension to prevent alveolar collapse and improve lung compliance for optimal gas exchange.

4. What is the primary purpose of conducting an experiment?

• A. to test a hypothesis
• B. to collect data
• C. to identify a control state
• D. to choose variables

Correct answer: A

Rationale: The correct answer is A: 'to test a hypothesis.' The primary purpose of conducting an experiment is to test a hypothesis. This process allows researchers to gather empirical evidence to either support or refute a proposed hypothesis. By systematically manipulating variables and observing outcomes, scientists can draw conclusions about the relationships between these variables. Choice B, 'to collect data,' is a common step within an experiment, but the ultimate goal is to test a specific hypothesis. Choice C, 'to identify a control state,' is not the primary purpose but rather a methodological consideration within an experiment to ensure reliable results. Choice D, 'to choose variables,' is a step that is typically done before conducting the experiment and is not the primary purpose of the experiment itself.

5. Which of the following is a property of amphiprotic substances?

• A. React with acids only
• B. React with bases only
• C. Can act as both acids and bases
• D. Are inert in chemical reactions

Correct answer: C

Rationale: The correct answer is C: Can act as both acids and bases. Amphiprotic substances have the ability to donate a proton (act as an acid) or accept a proton (act as a base) depending on the reaction conditions. This dual nature allows them to participate in a wide range of chemical reactions, making them versatile and important in various chemical processes. Choices A and B are incorrect because amphiprotic substances are not limited to reacting with only acids or bases; they can interact with both. Choice D is incorrect because amphiprotic substances are not inert; they actively participate in chemical reactions by donating or accepting protons.

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