Nursing Elites

1. Why are elements in Group 18 (Noble gases) generally unreactive?

• A. They have high atomic masses
• B. They lack valence electrons
• C. Their outermost electron shells are completely filled
• D. They exist as single atoms, not molecules

Correct answer: C

Rationale: Elements in Group 18 (Noble gases) are generally unreactive because their outermost electron shells are completely filled. This results in high stability and low reactivity since they have achieved a full valence shell configuration, making them less likely to gain, lose, or share electrons with other atoms. The full valence shell configuration leads to a minimal tendency for these elements to form chemical bonds, hence exhibiting low reactivity. Choices A, B, and D are incorrect because high atomic masses, lack of valence electrons, and existing as single atoms do not directly contribute to the unreactivity of noble gases. It is the full valence shell configuration that is the primary reason for their inert nature.

2. What is the muscular tube that connects the outer surface to the cervix in a woman's birth canal referred to as?

• A. The uterus
• B. The cervix
• C. The vagina
• D. The ovaries

Correct answer: C

Rationale: The correct answer is C, 'The vagina.' The muscular tube that connects the outer surface to the cervix in a woman's birth canal is called the vagina. The vagina serves as the passageway for menstrual flow, sexual intercourse, and childbirth. The cervix, not the uterus, connects the vagina to the uterus. The ovaries, on the other hand, are the organs responsible for producing eggs and female hormones, but they are not the muscular tube connecting the outer surface to the cervix in the birth canal.

3. Which element is essential for the formation of hemoglobin?

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

Correct answer: B

Rationale: The correct answer is Iron. Iron is essential for the formation of hemoglobin, the protein in red blood cells that binds and transports oxygen throughout the body. Calcium (Choice A), Potassium (Choice C), and Sodium (Choice D) are not directly involved in the formation of hemoglobin and its oxygen-carrying function.

4. What is the product of the reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH)?

• A. NaCl + H2O
• B. NaOH + HCl
• C. Na2Cl + H2O
• D. NaClO3 + H2

Correct answer: A

Rationale: When hydrochloric acid (HCl) reacts with sodium hydroxide (NaOH), it forms sodium chloride (NaCl) and water (H2O) according to the following chemical equation: HCl + NaOH -> NaCl + H2O. Therefore, the correct answer is NaCl + H2O (Choice A). This reaction is a classic acid-base neutralization reaction where the acid (HCl) reacts with the base (NaOH) to form a salt (NaCl) and water (H2O). Choice B (NaOH + HCl) is incorrect because the order of the reactants matters in a chemical reaction, and in this case, HCl is the acid reacting with NaOH. Choices C (Na2Cl + H2O) and D (NaClO3 + H2) are incorrect because they do not represent the products of the reaction between HCl and NaOH as per the balanced chemical equation.

5. Which type of epithelium lines the inner surface of the oral cavity, providing a barrier against external insults?

• A. Simple squamous epithelium
• B. Stratified squamous epithelium
• C. Simple columnar epithelium
• D. Pseudostratified columnar epithelium

Correct answer: B

Rationale: The oral cavity is constantly exposed to mechanical stress and potential injury from food particles and other external factors. To protect against these insults, a strong and resilient epithelium is needed. Stratified squamous epithelium is the best choice for lining the oral cavity due to its multiple layers of cells. This type of epithelium provides a robust barrier that can withstand abrasion and protect the underlying tissues. Simple squamous epithelium (choice A) is too thin and not suitable for a protective function. Simple columnar epithelium (choice C) is more suited for absorption and secretion functions, not protection against mechanical stress. Pseudostratified columnar epithelium (choice D) is found in respiratory passages and functions in mucociliary clearance, not in providing a protective barrier against external insults in the oral cavity.

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