Nursing Elites

1. What phenomenon explains the formation of rainbows in the sky?

• A. Diffraction
• B. Interference
• C. Refraction and dispersion of sunlight by water droplets
• D. Reflection from clouds

Correct answer: C

Rationale: Rainbows are formed due to the refraction and dispersion of sunlight by water droplets in the atmosphere. When sunlight enters a water droplet, it is refracted, then internally reflected, and finally refracted again as it exits the droplet. This dispersion of light into its component colors creates the beautiful rainbow we see in the sky. Choice A, diffraction, involves bending of light around obstacles or through narrow openings, not the splitting of light into colors as seen in rainbows. Choice B, interference, refers to the phenomenon where two or more light waves overlap and interact, producing a pattern of light and dark bands, which is not the case with rainbows. Choice D, reflection from clouds, does not accurately describe the process involved in the formation of rainbows through refraction and dispersion of light by water droplets.

2. If you compare a 1 M solution of NaCl to a 1 M solution of glucose (C6H12O6) in water, which solution would have the higher boiling point?

• A. The NaCl solution
• B. The glucose solution
• C. They would have the same boiling point
• D. It depends on the temperature

Correct answer: A

Rationale: 1. Boiling point elevation: When a solute is added to a solvent, it raises the boiling point of the solution compared to the pure solvent. This phenomenon is known as boiling point elevation. 2. Van't Hoff factor: The extent of boiling point elevation depends on the number of particles the solute dissociates into in the solution. NaCl dissociates into two ions (Na+ and Cl-) in water, while glucose does not dissociate into ions. Therefore, NaCl has a higher Van't Hoff factor than glucose. 3. Colligative properties: Boiling point elevation is a colligative property, meaning it depends on the concentration of the solute particles, not the identity of the solute. Since both NaCl and glucose are 1 M solutions, the NaCl solution will have a higher boiling point due to its higher Van't Hoff factor. 4. Conclusion: The NaCl solution

3. What is the diastole cycle in the heart?

• A. Relaxation of the heart
• B. Contraction of the heart
• C. Pulse rate of the heart
• D. Blood circulation

Correct answer: A

Rationale: The diastole cycle in the heart refers to the relaxation phase, where the heart chambers relax and fill with blood. This phase is crucial for the heart to refill and prepare for the next contraction (systole), which pumps blood out of the heart. Therefore, the correct answer is choice A, 'Relaxation of the heart.' Choices B, C, and D are incorrect in the context of cardiac physiology. Choice B, 'Contraction of the heart,' refers to systole, the phase of heart contraction. Choice C, 'Pulse rate of the heart,' is related to the number of heartbeats per minute, not the diastole cycle specifically. Choice D, 'Blood circulation,' is a broader term that encompasses the entire circulatory system rather than focusing on the heart's specific relaxation phase.

4. Which gas is the most abundant in Earth's atmosphere?

• A. Nitrogen
• B. Oxygen
• C. Carbon dioxide
• D. Argon

Correct answer: A

Rationale: Nitrogen is the most abundant gas in Earth's atmosphere, constituting approximately 78% of the air we breathe. It is essential for various biological processes, including plant growth and nitrogen fixation. Moreover, nitrogen is a key component of the greenhouse effect, playing a crucial role in regulating the planet's temperature. Oxygen, while important for respiration, comprises about 21% of the atmosphere. Carbon dioxide, though vital for photosynthesis and a greenhouse gas, is present in much lower concentrations than nitrogen. Argon, an inert gas, is a minor component of the atmosphere.

5. The tonsils and adenoids, located in the throat, are part of the:

• A. Lymphatic system
• B. Endocrine system
• C. Respiratory system
• D. Digestive system

Correct answer: A

Rationale: The tonsils and adenoids are part of the lymphatic system, not the respiratory, endocrine, or digestive systems. The lymphatic system plays a crucial role in the body's defense against infections and diseases by producing white blood cells and lymphatic fluid, which help in filtering harmful substances. The respiratory system is primarily responsible for breathing and gas exchange in the body, the endocrine system regulates hormones, and the digestive system is involved in the breakdown and absorption of nutrients from food. Therefore, the correct answer is the lymphatic system.

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