Nursing Elites

1. What is the general formula for an alkyl halide?

• A. CnH2n
• B. CnH2n+2
• C. CnH2n-1X
• D. CnH2nO

Correct answer: C

Rationale: The general formula for an alkyl halide is \(C_nH_{2n-1}X\), where X represents a halogen (e.g., F, Cl, Br, I).

2. What is the coefficient of oxygen in the balanced chemical equation for the combustion of methane (CH4)?

• A. 1
• B. 2
• C. 3
• D. 4

Correct answer: b

Rationale: The balanced equation is CH4 + 2O2 → CO2 + 2H2O, so the coefficient of oxygen is 2.

3. Two cars with different masses collide head-on. Which car experiences a greater change in momentum?

• A. The car with the larger mass
• B. The car with the smaller mass
• C. Both cars experience the same change in momentum
• D. It depends on the initial velocities of the cars

Correct answer: B

Rationale: The car with the smaller mass. Although momentum is conserved in the collision, the change in momentum is inversely proportional to mass. Therefore, the car with the smaller mass will experience a larger relative change.

4. Which hormone, produced by the pancreas, is released in response to low blood sugar levels and stimulates the release of glucose into the bloodstream?

• A. Insulin
• B. Glucagon
• C. Cortisol
• D. Thyroxine

Correct answer: b

Rationale: The correct answer is B: Glucagon. Glucagon is a hormone produced by the pancreas that is released in response to low blood sugar levels, also known as hypoglycemia. When blood sugar levels drop, glucagon acts to stimulate the liver to release stored glucose into the bloodstream, helping to raise blood sugar levels back to a normal range. Insulin, on the other hand, is released in response to high blood sugar levels and helps to lower blood sugar by promoting the uptake of glucose by cells. Cortisol is a stress hormone produced by the adrenal glands, and thyroxine is a hormone produced by the thyroid gland that regulates metabolism. Therefore, glucagon is the hormone specifically responsible for stimulating the release of glucose into the bloodstream in response to low blood sugar levels.

5. A study finds a link between increased screen time and lower academic performance. What additional information would be most helpful in interpreting this finding?

• A. The average socioeconomic status of the study participants.
• B. The specific types of screen activities participants engaged in.
• C. Whether the students had access to healthy meals and snacks.
• D. The participants' ages and grade levels.

Correct answer: B

Rationale: Knowing the specific types of screen activities participants engaged in would provide crucial context for interpreting the link between increased screen time and lower academic performance. For example, if the majority of screen time was spent on educational apps or programs, the impact on academic performance may differ compared to if the screen time was mostly spent on social media or gaming. Understanding the nature of screen activities can help determine the potential mechanisms behind the observed relationship.

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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