Nursing Elites

1. What is the main function of valence electrons in chemical bonding?

• A. They are responsible for holding the nucleus together.
• B. They are involved in forming bonds with other atoms.
• C. They determine the element's physical properties.
• D. They play no role in chemical reactions.

Correct answer: B

Rationale: Valence electrons are the electrons in the outermost energy level of an atom. These electrons are involved in forming bonds with other atoms, which is crucial for chemical bonding. By participating in bonding, valence electrons determine an atom's ability to form compounds and engage in chemical reactions. Therefore, the primary function of valence electrons is to facilitate the formation of bonds between atoms, making option B the correct answer. Choices A, C, and D are incorrect because valence electrons primarily influence chemical bonding by participating in the formation of bonds between atoms, rather than holding the nucleus together, determining physical properties, or having no role in chemical reactions.

2. What is the primary function of the respiratory system?

• A. To digest food
• B. To transport nutrients
• C. To exchange gases
• D. To regulate body temperature

Correct answer: C

Rationale: The correct answer is C: To exchange gases. The primary function of the respiratory system is to facilitate the exchange of gases, specifically oxygen and carbon dioxide, between the body and the environment. This process is essential for cellular respiration, where oxygen is taken in and carbon dioxide is removed. Choices A, B, and D are incorrect. Digesting food is primarily the function of the digestive system, transporting nutrients is the role of the circulatory system, and regulating body temperature is primarily managed by the integumentary system and the nervous system, not the respiratory system.

3. Which type of carbohydrate is the main component of the cell wall in plant cells?

• A. Starch
• B. Glucose
• C. Cellulose
• D. Chitin

Correct answer: C

Rationale: The correct answer is 'Cellulose.' Cellulose is the main component of the cell wall in plant cells, providing structural support and rigidity. Starch, while a carbohydrate, is a storage form of glucose in plants and not a component of the cell wall. Glucose is a simple sugar that can be used as an energy source but is not the main component of the cell wall. Chitin is a structural carbohydrate found in the exoskeleton of arthropods and fungi, not in plant cell walls.

4. The van't Hoff factor (i) accounts for the number of particles a solute dissociates into in solution. For a compound that dissociates completely in water, i would be...

• A. 0
• B. Less than 1
• C. 1
• D. More than 1

Correct answer: D

Rationale: The van't Hoff factor (i) represents the number of particles a solute dissociates into in solution. For a compound that dissociates completely in water, i would be more than 1 because it breaks apart into more particles than the original compound. This is due to complete dissociation leading to an increase in the number of particles in solution, resulting in i being greater than 1. Choice A is incorrect as a compound that dissociates completely will not have an i value of 0. Choice B is incorrect because when a compound dissociates completely, the van't Hoff factor is not less than 1. Choice C is incorrect as a compound that dissociates completely will not have an i value of 1, but rather more than 1 due to the increased number of particles in solution.

5. What type of tissue is bone composed of?

• A. Epithelial tissue
• B. Connective tissue
• C. Hard connective tissue
• D. Muscle tissue

Correct answer: B

Rationale: Bone is composed of connective tissue. Connective tissues are characterized by having cells scattered within an extracellular matrix. In the case of bone, the extracellular matrix is mineralized, giving bone its hardness and strength. Choice A, epithelial tissue, is not correct as bone is not primarily composed of epithelial cells. Choice C, hard connective tissue, is not a recognized category of tissue in the scientific classification; bone is classified under connective tissue. Choice D, muscle tissue, is incorrect as bone and muscle tissues are distinct types of tissues with different structures and functions.

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