Nursing Elites

1. What kind of lens focuses parallel light rays to a single point?

• A. Concave lens
• B. Convex lens
• C. Cylindrical lens
• D. Plano lens

Correct answer: B

Rationale: Convex lenses (converging lenses) bend incoming light rays inwards, focusing them to a point called the focal point.

2. The defining characteristic of an element is determined by the number of:

• A. Neutrons in its nucleus
• B. Electrons surrounding the nucleus
• C. Protons in its nucleus
• D. All of the above

Correct answer: C

Rationale: The correct answer is C: 'Protons in its nucleus.' An element is defined by the number of protons in its nucleus, known as the atomic number. This number determines the element's identity and its placement on the periodic table. Neutrons and electrons play important roles in an atom, but they do not define the element itself. Neutrons contribute to the atom's mass, while electrons are involved in chemical reactions and bonding. Therefore, the number of protons is the defining characteristic of an element.

3. When making a dilution, you...

• A. Add more solute to a concentrated solution
• B. Change the temperature of the solution
• C. Decrease the concentration of a solution
• D. All of the above

Correct answer: C

Rationale: The correct answer is C: 'Decrease the concentration of a solution.' When making a dilution, you decrease the concentration of a solution by adding more solvent, not solute. Adding more solute to a concentrated solution would increase the concentration, not dilute it. Changing the temperature of the solution does not directly relate to dilution. Therefore, the only correct statement related to the process of making a dilution is that you decrease the concentration of the solution by adding more solvent, making option C the correct answer.

4. Which of the following minerals is important for bone health and is stored in bones by the skeletal system?

• A. Iron
• B. Sodium
• C. Calcium
• D. Magnesium

Correct answer: C

Rationale: The correct answer is C: Calcium. Calcium is essential for maintaining strong and healthy bones. It is a key mineral stored in bones by the skeletal system, where it provides structural support and strength. Adequate calcium intake is crucial for preventing bone diseases like osteoporosis and ensuring proper bone formation and density. Iron (A), Sodium (B), and Magnesium (D) are important minerals for various bodily functions but are not primarily responsible for bone health and storage in bones by the skeletal system.

5. Which of the following reagents can be used to convert a primary alcohol to an alkyl halide?

• A. HI
• B. H2O
• C. NaOH
• D. SOCl2

Correct answer: D

Rationale: The correct answer is D: SOCl2. SOCl2, also known as thionyl chloride, is commonly used to convert primary alcohols to alkyl halides through an SN2 mechanism. Thionyl chloride reacts with the alcohol to form an alkyl chloride, replacing the hydroxyl group. Option A, HI (hydroiodic acid), is typically used to convert alcohols to alkyl iodides, while option B, H2O (water), and option C, NaOH (sodium hydroxide), are not reagents suitable for this specific transformation. Therefore, SOCl2 is the most appropriate reagent for converting a primary alcohol to an alkyl halide.

6. Which of the following factors does NOT affect the rate of dissolution of a solute in a solvent?

• A. Temperature
• B. Pressure
• C. Surface area
• D. Particle size

Correct answer: B

Rationale: Pressure does not affect the rate of dissolution of a solute in a solvent. The factors that do affect the rate of dissolution include temperature, surface area, and particle size. Temperature generally increases the rate of dissolution as it provides more energy for the solute particles to break apart and mix with the solvent. Increasing the surface area of the solute by grinding it into smaller particles or increasing its contact area with the solvent can also speed up dissolution. Similarly, reducing the particle size of the solute can increase the rate of dissolution by providing more surface area for interaction with the solvent.

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