Nursing Elites

1. What happens during a physical change in matter?

• A. A new substance with different properties is formed
• B. The chemical composition of the substance changes
• C. The original substance can be recovered by physical means
• D. Energy is either released or absorbed

Correct answer: C

Rationale: During a physical change in matter, the original substance undergoes a change in its physical state or appearance without any change in its chemical composition. This means that the original substance can be recovered by physical means, such as melting, freezing, boiling, or condensing. No new substance is formed (option A), the chemical composition remains the same (option B), and energy changes can occur but are not a defining characteristic of a physical change (option D).

2. Which muscle plays a significant role in the process of forced exhalation by contracting to reduce the thoracic cavity volume?

• A. Diaphragm
• B. External intercostal muscles
• C. Internal intercostal muscles
• D. Abdominal muscles

Correct answer: C

Rationale: The correct answer is C: Internal intercostal muscles. During forced exhalation, these muscles contract to depress the ribs and decrease the thoracic cavity volume, assisting in pushing air out of the lungs. The diaphragm is primarily responsible for inhalation by contracting to increase thoracic cavity volume. External intercostal muscles aid in inhalation by elevating the ribs. Abdominal muscles are involved in activities like coughing, sneezing, and forced exhalation by compressing the abdominal contents to further reduce thoracic volume. Therefore, the internal intercostal muscles have a significant role in forced exhalation.

3. What is the net ionic equation for the reaction: 2HCl(aq) + Ba(OH)2(aq) → 2H2O(l) + BaCl2(aq)?

• A. 2H+(aq) + 2OH-(aq) → 2H2O(l)
• B. 2HCl(aq) + Ba(OH)2(aq) → BaCl2(aq) + 2H2O(l)
• C. 2H+(aq) + Ba2+(aq) → Ba2+(aq) + 2H+(aq)
• D. Ba(OH)2(aq) + HCl(aq) → BaCl2(aq) + 2H2O(l)

Correct answer: a

Rationale: The net ionic equation includes only the species that undergo a change during the reaction.

4. How does RNA polymerase differ from DNA polymerase?

• A. Both enzymes are identical in function and structure.
• B. RNA polymerase does not require a primer to initiate RNA synthesis.
• C. RNA polymerase can synthesize both RNA and DNA.
• D. RNA polymerase can only synthesize RNA, unlike DNA polymerase.

Correct answer: B

Rationale: Rationale: A) This statement is incorrect. RNA polymerase and DNA polymerase are not identical in function and structure. They have different roles in the cell. B) This statement is correct. Unlike DNA polymerase, RNA polymerase does not require a primer to initiate RNA synthesis. RNA polymerase can start the synthesis of RNA de novo. C) This statement is incorrect. RNA polymerase is specialized for synthesizing RNA, not DNA. DNA polymerase is responsible for synthesizing DNA. D) This statement is correct. RNA polymerase can only synthesize RNA, while DNA polymerase is responsible for synthesizing DNA.

5. What is the half-life of a radioactive isotope, and how does it relate to its decay rate?

• A. The time it takes for half of the initial sample to decay.
• B. The time it takes for all the sample to decay.
• C. The rate at which new isotopes are created.
• D. The energy released during decay.

Correct answer: A

Rationale: Half-life tells the time it takes for half of the original radioactive nuclei to decay, offering an indication of the decay rate.

6. What property of matter remains constant regardless of changes in its state?

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

Correct answer: a

Rationale: Mass remains constant for a given amount of matter, regardless of its state (solid, liquid, or gas) or its location in the universe. Explanation of other options:

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