Nursing Elites

1. In ecology, what defines a closed system?

• A. Exchanges energy but not matter
• B. Exchanges both energy and matter
• C. Exchanges neither energy nor matter
• D. Recycles nutrients efficiently

Correct answer: A

Rationale: In ecology, a closed system is one that does not exchange matter with its surroundings but can exchange energy. This means that while energy can enter or leave the system, the amount of matter within the system remains constant. Option A correctly defines a closed system in ecology. Choices B and C are incorrect as a closed system does not exchange matter or energy. Option D is unrelated to the concept of a closed system in ecology.

2. What defines the period of a wave?

• A. The time it takes for one complete wave cycle to pass a point
• B. The distance between two adjacent crests or troughs
• C. The number of waves passing a point per unit time
• D. The maximum displacement of particles in a medium due to the wave

Correct answer: A

Rationale: The period of a wave is defined as the time it takes for one complete wave cycle to pass a point. It is a crucial parameter in wave analysis and is typically measured in seconds. The period is directly related to the frequency of the wave, as they are reciprocals of each other. Therefore, the correct answer is the time it takes for one complete wave cycle to pass a point (choice A). The period is not related to the number of waves passing a point per unit time (choice C), the distance between two adjacent crests or troughs (choice B), or the maximum displacement of particles in a medium due to the wave (choice D).

3. Which property of a substance describes its ability to conduct heat or electricity?

• A. Reactivity
• B. Conductivity
• C. Density
• D. Viscosity

Correct answer: B

Rationale: Conductivity is the correct property that describes a substance's ability to conduct heat or electricity. Reactivity is related to how readily a substance undergoes chemical reactions, not its ability to conduct heat or electricity. Density refers to the mass per unit volume of a substance, which is different from its ability to conduct heat or electricity. Viscosity measures a substance's resistance to flow, not its ability to conduct heat or electricity.

4. How is homeostasis defined?

• A. The ability of human beings to keep body weight within normal limits.
• B. The maintenance of a constant external temperature inside a room.
• C. The ingestion of enough food to prevent hunger pains.
• D. The tendency of the body to maintain a stable internal environment.

Correct answer: D

Rationale: Homeostasis is defined as the tendency of the body to maintain a stable internal environment despite external changes. This process involves regulating various physiological parameters such as body temperature, blood pressure, and glucose levels to ensure optimal functioning and health. Option A is incorrect as it specifically refers to body weight regulation, which is not the sole focus of homeostasis. Option B is incorrect as it describes maintaining a constant temperature in a room, rather than the internal environment of the body. Option C is incorrect as it only addresses the prevention of hunger pains through food ingestion, which is not the overarching concept of homeostasis.

5. How can the periodic table be used to predict the charge of an ion formed by an element?

• A. Look for elements with similar atomic weights.
• B. Identify the group number, which corresponds to the typical ionic charge.
• C. Calculate the difference between protons and electrons.
• D. Analyze the element's position within the period.

Correct answer: B

Rationale: The group number of an element on the periodic table corresponds to the number of valence electrons it has. Elements in the same group tend to form ions with the same charge. For example, elements in Group 1 typically form ions with a +1 charge, while elements in Group 17 typically form ions with a -1 charge. Therefore, by identifying the group number of an element, one can predict the typical ionic charge it will form. Choices A, C, and D are incorrect because predicting the charge of an ion is mainly based on the element's position in the periodic table, particularly the group number, which indicates the number of valence electrons and the typical ionic charge it may form.

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