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. Balance the chemical equation: C4H10 + O2 → CO2 + H2O. What is the coefficient for oxygen?

• A. 5
• B. 6
• C. 7
• D. 8

Correct answer: B

Rationale: To balance the chemical equation, we need to ensure that the number of each type of atom is the same on both sides of the equation. In this case, there are 10 oxygen atoms on the right side (5 in CO2 and 5 in H2O). To balance this, we need to add a coefficient of 6 in front of O2 on the left side, resulting in 6 O2 molecules. This change will give us a total of 12 oxygen atoms on both sides, making the equation balanced. Choice A (5) is incorrect because it does not account for all the oxygen atoms present in the products. Choices C (7) and D (8) are incorrect as they would result in an imbalance in the number of oxygen atoms on both sides of the equation.

3. The body's first line of defense against pathogens is the innate immune system. Which of the following is NOT a component of the innate immune system?

• A. Physical barriers like skin and mucous membranes
• B. Phagocytes that engulf and destroy pathogens
• C. Inflammatory response to isolate and contain infection
• D. Production of antibodies specific to a particular pathogen

Correct answer: D

Rationale: The production of antibodies specific to a particular pathogen is a function of the adaptive immune system, not the innate immune system. The innate immune system provides immediate, non-specific defense mechanisms against pathogens, including physical barriers, phagocytes, and inflammatory responses. Choices A, B, and C are all correct components of the innate immune system. Physical barriers like skin and mucous membranes act as the first line of defense, preventing pathogens from entering the body. Phagocytes are specialized cells that engulf and destroy pathogens, while the inflammatory response helps isolate and contain infections to prevent their spread.

4. Which division of the nervous system is responsible for the 'fight or flight' response, preparing the body to respond to stressful situations?

• A. Somatic nervous system
• B. Autonomic nervous system
• C. Peripheral nervous system
• D. Central nervous system

Correct answer: B

Rationale: The autonomic nervous system is correctly identified as the division responsible for the 'fight or flight' response, which readies the body to react to stressful situations. This system regulates involuntary bodily functions, such as heart rate, pupil dilation, and adrenaline release during stress. The somatic nervous system controls voluntary movements and skeletal muscle activity, not the automatic responses seen in the 'fight or flight' reaction. The peripheral nervous system connects the central nervous system to the body's organs and limbs, facilitating communication, while the central nervous system, comprising the brain and spinal cord, serves as the primary control center of the body, integrating and processing information.

5. Which of the following is NOT a function of the cardiovascular system?

• A. Transporting oxygen to cells
• B. Maintaining blood pressure
• C. Carrying waste products to the kidneys for removal
• D. Initiating the immune response

Correct answer: D

Rationale: The cardiovascular system is responsible for transporting oxygen to cells (A), maintaining blood pressure (B), and carrying waste products to the kidneys for removal (C). Initiating the immune response (D) is not a function of the cardiovascular system. The immune response is primarily carried out by the immune system, which includes organs like the spleen, thymus, and lymph nodes. Therefore, option D is the correct answer as it pertains to a function outside the scope of the cardiovascular system, making it the odd one out among the given choices.

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