Nursing Elites

1. Which of the following serves as a standard or series of standards for comparing the results of an experiment?

• A. A control
• B. A variable
• C. A constant
• D. Collected data

Correct answer: A

Rationale: A control is a standard used to compare the outcomes of an experiment and is crucial for determining the effect of the variables being tested. It helps isolate and measure the impact of the independent variable by providing a baseline for comparison. While variables may change, constants remain consistent, and collected data is the information obtained from the experiment. A control specifically serves as the standard for comparison in an experiment, making it the correct choice. Variables, although important, are what are being altered and tested in an experiment, constants are factors that are kept consistent throughout the experiment, and collected data is the information gathered from the experiment, none of which specifically serve as the standard for comparison.

2. 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.

3. What is the function of valves in arteries?

• A. To maintain high blood pressure for the proper diffusion of nutrients in capillaries.
• B. To prevent backflow of blood due to high pressure away from the heart.
• C. As a vestigial trait from evolution, like the appendix, that serves no purpose.
• D. Valves are absent in arteries but present in veins.

Correct answer: B

Rationale: Valves in arteries serve the crucial function of preventing backflow of blood. Arteries carry blood at high pressure away from the heart, and the valves ensure that blood flows in one direction, towards the capillaries, to maintain efficient circulation. Without these valves, there would be a risk of blood flowing backward, compromising the effectiveness of blood circulation in the body. Choices A, C, and D are incorrect. Choice A incorrectly suggests that valves maintain high blood pressure for nutrient diffusion in capillaries, which is not their function. Choice C inaccurately compares valves to vestigial traits, like the appendix, implying they serve no purpose, which is untrue. Choice D is incorrect as valves are indeed present in arteries to regulate blood flow, not just in veins.

4. Photons, the basic unit of light, are:

• A. Charged particles
• B. Packets of energy with wave-particle duality
• C. Electromagnetic waves only
• D. Always absorbed by matter

Correct answer: B

Rationale: Photons are not charged particles; they are packets of energy that exhibit wave-particle duality, meaning they can behave as both particles and waves. While photons are part of the electromagnetic spectrum, they are not electromagnetic waves themselves but rather discrete energy packets. They are not always absorbed by matter; they can be reflected, transmitted, or scattered.

5. What determines the magnitude of the frictional force acting on a book sliding across a table?

• A. Only the mass of the book
• B. Only the normal force from the table
• C. Both the mass of the book and the normal force from the table
• D. Neither the mass of the book nor the normal force from the table

Correct answer: C

Rationale: The magnitude of the frictional force acting on the book sliding across a table is determined by both the mass of the book and the normal force from the table. Frictional force is proportional to the normal force (which is influenced by the weight of the book, i.e., its mass) and is affected by the surfaces in contact and other friction-related factors. Therefore, both the mass of the book and the normal force from the table are essential in determining the frictional force experienced by the book during its sliding motion. Choices A, B, and D are incorrect because friction is a result of the interaction between the surfaces and is influenced by both the mass of the object and the normal force acting on it.

Similar Questions