Nursing Elites

1. How does the Law of Conservation of Mass apply to this reaction: 2H₂ + O₂ → 2H₂O?

• A. Electrons are not lost.
• B. The hydrogen does not lose mass.
• C. New water molecules are formed.
• D. There is no decrease or increase in matter.

Correct answer: D

Rationale: The Law of Conservation of Mass states that matter cannot be created or destroyed in a chemical reaction. In the given reaction, 2 moles of hydrogen combine with 1 mole of oxygen to form 2 moles of water. The total mass of the reactants (hydrogen and oxygen) is equal to the total mass of the products (water), meaning there is no decrease or increase in matter. The total mass of the system remains constant, demonstrating the conservation of mass. Choices A, B, and C are incorrect because the conservation of mass does not specifically relate to electrons, individual elements (like hydrogen), or the formation of new molecules; instead, it focuses on the overall mass of the system before and after the reaction.

2. Dietary fiber, although not fully digested by the body, plays a crucial role in digestion. What is one of the main benefits of consuming sufficient dietary fiber?

• A. Provides a concentrated source of energy
• B. Aids in the absorption of vitamins and minerals
• C. Promotes satiety and gut health
• D. Breaks down complex carbohydrates

Correct answer: C

Rationale: Consuming sufficient dietary fiber promotes satiety and gut health by adding bulk to the diet, helping with feelings of fullness, and supporting healthy digestion. Additionally, fiber aids in regulating bowel movements and maintaining a healthy gut microbiota, contributing to overall digestive wellness. It does not provide a concentrated source of energy as fiber is not fully digested for energy production, nor does it directly aid in the absorption of vitamins and minerals. Fiber does not break down complex carbohydrates but rather assists in their digestion and absorption by slowing down the process, which helps in maintaining stable blood sugar levels and promoting better overall health.

3. What is the process of converting lactic acid back into pyruvate called?

• A. Glycolysis
• B. Gluconeogenesis
• C. Cori cycle
• D. Oxidative phosphorylation

Correct answer: C

Rationale: A) Glycolysis is the process of breaking down glucose into pyruvate. B) Gluconeogenesis is the process of synthesizing glucose from non-carbohydrate sources. C) The Cori cycle is the process by which lactic acid produced by anaerobic metabolism in muscles is transported to the liver and converted back into glucose or pyruvate. D) Oxidative phosphorylation is the process by which ATP is synthesized using energy derived from the transfer of electrons in the electron transport chain.

4. In which medium does light propagate at its highest speed?

• A. Air
• B. Water
• C. Glass
• D. Diamond

Correct answer: A

Rationale: Light travels at its highest speed in a vacuum. However, among the options provided, air is the closest medium to a vacuum, making it the correct answer. In general, light travels slower in denser mediums due to interactions with atoms and molecules in the medium. Water, glass, and diamond are denser mediums compared to air, causing light to propagate at slower speeds in these materials, hence making them incorrect choices.

5. What is the function of the esophagus in the digestive system?

• A. To absorb nutrients
• B. To transport food from the mouth to the stomach
• C. To break down food
• D. To absorb water

Correct answer: B

Rationale: The esophagus functions to transport food from the mouth to the stomach through a process called peristalsis, which involves a series of muscle contractions that push the food downward along the digestive tract. Absorbing nutrients (Choice A) is typically done in the small intestine, breaking down food (Choice C) is primarily the role of the stomach and small intestine, and absorbing water (Choice D) mainly occurs in the large intestine.

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