Nursing Elites

1. Which of the following statements is true about the dependent variable?

• A. A factor that remains constant during the experiment
• B. A factor with data typically plotted on the x-axis
• C. A factor that is measured during an experiment
• D. A factor with data typically plotted on the y-axis

Correct answer: C

Rationale: The correct answer is C. The dependent variable is the factor that is being measured or observed in an experiment. It is the outcome that is affected by changes in the independent variable. In graphical representations, the dependent variable is usually plotted on the y-axis, not the x-axis. Choice A is incorrect because a factor that remains constant is referred to as a constant, not a dependent variable. Choice B is incorrect as the independent variable's data is typically plotted on the x-axis. Choice D is incorrect because the dependent variable's data is usually plotted on the y-axis. Therefore, choice C accurately describes the dependent variable.

2. Why are elements in Group 18 (Noble gases) generally unreactive?

• A. They have high atomic masses
• B. They lack valence electrons
• C. Their outermost electron shells are completely filled
• D. They exist as single atoms, not molecules

Correct answer: C

Rationale: Elements in Group 18 (Noble gases) are generally unreactive because their outermost electron shells are completely filled. This results in high stability and low reactivity since they have achieved a full valence shell configuration, making them less likely to gain, lose, or share electrons with other atoms. The full valence shell configuration leads to a minimal tendency for these elements to form chemical bonds, hence exhibiting low reactivity. Choices A, B, and D are incorrect because high atomic masses, lack of valence electrons, and existing as single atoms do not directly contribute to the unreactivity of noble gases. It is the full valence shell configuration that is the primary reason for their inert nature.

3. A ball is rolling across the floor and comes to a stop on its own. What force caused the ball to stop?

• A. Gravitational force
• B. Normal force from the floor
• C. Air resistance
• D. None of the above

Correct answer: C

Rationale: The force that caused the ball to stop rolling across the floor is air resistance. As the ball moves through the air, air resistance acts in the opposite direction of its motion, gradually slowing it down until it comes to a stop. In this scenario, the ball is not in contact with the floor, so the normal force from the floor does not play a role in stopping the ball. Gravitational force acts to pull objects towards the center of the Earth and would not directly stop the ball in this situation. Therefore, air resistance is the force that opposes the motion of the rolling ball and causes it to come to a stop.

4. What is the primary function of the large intestine?

• A. To digest food
• B. To absorb water and form feces
• C. To absorb proteins
• D. To regulate blood pressure

Correct answer: B

Rationale: The correct answer is B. The primary function of the large intestine is to absorb water from digested food and form feces for elimination. It does not primarily digest food, absorb proteins, or regulate blood pressure. Choice A is incorrect because the large intestine does not digest food but rather absorbs nutrients and water. Choice C is incorrect as the absorption of proteins primarily occurs in the small intestine. Choice D is incorrect as the regulation of blood pressure is not a primary function of the large intestine.

5. In an SN2 reaction, what affects the rate of the reaction?

• A. Only the concentration of the nucleophile
• B. Only the concentration of the electrophile
• C. Neither the concentration of the nucleophile nor the electrophile
• D. Both the concentration of the nucleophile and the electrophile

Correct answer: D

Rationale: In an SN2 reaction, the rate of the reaction is affected by both the concentration of the nucleophile and the electrophile. The rate-determining step involves the nucleophile attacking the electrophile, so the concentrations of both species will impact the reaction rate. Increasing the concentration of the nucleophile increases the frequency of nucleophilic attacks, while increasing the concentration of the electrophile provides more opportunities for the nucleophile to react. Therefore, the correct answer is that both the concentration of the nucleophile and the electrophile affect the rate of the SN2 reaction. Choices A, B, and C are incorrect as they do not consider the interplay between the nucleophile and the electrophile in determining the overall reaction rate in an SN2 mechanism.

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