Nursing Elites

1. Which statement is TRUE about valence electrons?

• A. They are located in the innermost electron shell.
• B. They have the highest binding energy to the nucleus.
• C. They are most likely to participate in chemical bonding.
• D. They have no influence on the element's chemical properties.

Correct answer: C

Rationale: Valence electrons are the outermost electrons in an atom's electron cloud and are crucial in forming chemical bonds with other atoms. These electrons determine the reactivity and chemical properties of an element, making option C the correct statement. Option A is incorrect as valence electrons are found in the outer shell, not the innermost shell. Option B is incorrect because valence electrons have lower binding energy compared to inner electrons. Option D is incorrect since valence electrons play a significant role in an element's chemical behavior.

2. Which kingdom primarily consists of multicellular, photosynthetic organisms with cell walls made of cellulose?

• A. Animalia
• B. Fungi
• C. Plantae
• D. Protista

Correct answer: C

Rationale: A) Animalia consists of multicellular organisms that lack cell walls and are heterotrophic. Therefore, it does not primarily consist of photosynthetic organisms with cell walls made of cellulose. B) Fungi are multicellular organisms with cell walls made of chitin and are heterotrophic, so they do not fit the description. C) Plantae primarily consists of multicellular, photosynthetic organisms with cell walls made of cellulose. This accurately describes plants. D) Protista is a diverse kingdom that includes unicellular and multicellular organisms with varying characteristics, but it does not primarily consist of multicellular, photosynthetic organisms with cell walls made of cellulose.

3. What is the primary hormone released by the parathyroid glands?

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

Correct answer: C

Rationale: The primary hormone released by the parathyroid glands is parathyroid hormone (PTH). PTH plays a crucial role in regulating calcium and phosphorus levels in the body by increasing calcium levels in the blood through various mechanisms, such as promoting calcium release from bones and increasing calcium absorption in the intestines. Insulin is produced by the pancreas and regulates blood sugar levels, calcitonin is produced by the thyroid gland and helps lower blood calcium levels, and thyroxine is a hormone produced by the thyroid gland that regulates metabolism. Therefore, choices A, B, and D are incorrect as they are not the primary hormone released by the parathyroid glands.

4. What is the name of the wart-like growths caused by the human papillomavirus (HPV)?

• A. Keloids
• B. Keloids
• C. Papillomas
• D. Carcinomas

Correct answer: C

Rationale: The correct answer is 'Papillomas.' Papillomas are benign wart-like growths caused by the human papillomavirus (HPV). Keloids are raised scars that occur at the site of an injury due to excessive collagen formation, while carcinomas are malignant tumors arising from epithelial cells. When identifying the growths specifically related to HPV, papillomas are the most appropriate term.

5. In the reaction 2H2 + O2 → 2H2O, how many moles of oxygen are required to react completely with 4 moles of hydrogen?

• A. 1
• B. 2
• C. 3
• D. 4

Correct answer: B

Rationale: The balanced chemical equation indicates that 2 moles of H2 react with 1 mole of O2 to produce 2 moles of H2O. To determine how many moles of O2 are required to react with 4 moles of H2, you can use the mole ratio from the balanced equation: 2 moles of H2 react with 1 mole of O2. Therefore, to react completely with 4 moles of H2, you would need 2 moles of O2 (4 moles H2 ÷ 2 moles H2 per 1 mole O2). Hence, 2 moles of oxygen are required to react completely with 4 moles of hydrogen. Choices A, C, and D are incorrect because they do not reflect the correct stoichiometry as defined by the balanced chemical equation.

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