Nursing Elites

1. What element is responsible for the red color of blood?

• A. Magnesium
• B. Iron
• C. Copper
• D. Zinc

Correct answer: B

Rationale: The correct answer is B: Iron. Hemoglobin, the protein responsible for carrying oxygen in red blood cells, contains iron in its heme group, contributing to the blood's characteristic red color. Magnesium (choice A), copper (choice C), and zinc (choice D) are not responsible for the red color of blood. Magnesium is an essential mineral involved in various physiological processes, copper is a trace element important for enzyme function, and zinc is a micronutrient essential for multiple cellular functions but not related to the red color of blood.

2. Which term describes a substance's ability to undergo a change that transforms it into a different substance?

• A. Density
• B. Mass
• C. Reactivity
• D. Volume

Correct answer: C

Rationale: Reactivity refers to a substance's ability to undergo a change that transforms it into a different substance through a chemical reaction. In this context, reactivity specifically refers to the chemical behavior of a substance. Density, mass, and volume are physical properties of a substance and do not describe its ability to undergo a chemical change. Density is the mass per unit volume, mass is the amount of matter in an object, and volume is the amount of space occupied by an object. Therefore, reactivity is the most appropriate term to describe a substance's ability to undergo a transformation into a different substance.

3. Which nitrogenous bases pair with each other in DNA?

• A. A-G and T-C
• B. A-T and C-G
• C. A-T and T-T
• D. C-C and G-G

Correct answer: B

Rationale: In DNA, nitrogenous bases pair with each other in a specific manner known as complementary base pairing. Adenine (A) always pairs with Thymine (T), and Cytosine (C) always pairs with Guanine (G). This pairing is essential for maintaining the structure and function of DNA. Option B is the correct answer as it correctly identifies the nitrogenous bases that pair with each other in DNA. Choices A, C, and D are incorrect because they do not follow the established base pairing rules in DNA. A-T and C-G are the complementary base pairs in DNA, ensuring the stability and replication fidelity of the genetic material.

4. How can you predict the charge of an ion formed by an element based on its position on the periodic table?

• A. Look for elements with similar atomic weights
• B. Identify the group number, which often indicates the typical ionic charge
• C. Identify the period number to determine the ionic charge
• D. Analyze the element's position within the group

Correct answer: B

Rationale: The group number of an element on the periodic table often indicates the typical ionic charge it will form. Elements in the same group tend to have similar chemical properties, including the tendency to gain or lose electrons to achieve a stable electron configuration. This predictable pattern allows us to anticipate the charge of an ion formed by an element based on its position in the periodic table. Choices A, C, and D are incorrect because predicting the charge of an ion is primarily based on the element's group number, which reflects its valence electrons and typical ionic charge. Atomic weight (Choice A) and period number (Choice C) do not directly correlate with the ionic charge prediction, and analyzing the element's position within the group (Choice D) is less relevant than identifying the group number itself.

5. In physics, what does the term 'terminal velocity' refer to?

• A. Maximum velocity reached by an object in free fall
• B. Velocity when the object is at rest
• C. Instantaneous velocity of an object
• D. Velocity only reached by heavy objects

Correct answer: A

Rationale: Terminal velocity in physics refers to the maximum velocity achieved by an object in free fall when the force of gravity equals the force of air resistance. At terminal velocity, the object stops accelerating and maintains a constant speed. This occurs when the opposing forces are balanced, leading to no further increase in speed. Choice B is incorrect as velocity when the object is at rest is zero, not at terminal velocity. Choice C is incorrect as instantaneous velocity refers to the velocity at a specific moment in time, not the maximum speed reached in free fall. Choice D is incorrect because terminal velocity is not exclusive to heavy objects; all objects in free fall can reach terminal velocity under the right conditions.

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