Nursing Elites

1. What is the process called in which a substance changes from a gas to a liquid?

• A. Condensation.
• B. Evaporation.
• C. Sublimation.
• D. Vaporization.

Correct answer: A

Rationale: Condensation is indeed the correct answer. It is the process by which a substance changes from a gas to a liquid. This occurs when the temperature of a gas decreases enough for its particles to lose energy and come together to form a liquid. On the other hand, evaporation is the process of a liquid changing to a gas. Sublimation is the direct transition of a substance from a solid to a gas without passing through the liquid phase. Vaporization, on the other hand, is the general term for the process of a liquid changing to a gas, which includes both evaporation and boiling.

2. Which of the following is responsible for maintaining homeostasis in the body?

• A. Brainstem
• B. Hypothalamus
• C. Medulla oblongata
• D. Cerebrum

Correct answer: B

Rationale: The correct answer is the Hypothalamus (choice B). The hypothalamus plays a crucial role in maintaining homeostasis by regulating various bodily functions such as hunger, thirst, body temperature, and sleep cycles. While the brainstem (choice A) is involved in basic life functions like breathing and heart rate, it is not primarily responsible for maintaining homeostasis. The medulla oblongata (choice C) is part of the brainstem and controls vital autonomic functions like breathing and heart rate, but it is not the main regulator of homeostasis. The cerebrum (choice D) is responsible for higher brain functions such as thinking, memory, and voluntary movement, but it is not directly involved in maintaining overall bodily balance or homeostasis.

3. Which part of the ear is responsible for transmitting sound vibrations to the inner ear?

• A. Cochlea
• B. Ossicles
• C. Semicircular canals
• D. Eustachian tube

Correct answer: B

Rationale: The correct answer is B: Ossicles. The ossicles, consisting of the malleus, incus, and stapes, are located in the middle ear. They play a crucial role in transmitting sound vibrations from the eardrum to the inner ear, specifically to the cochlea. The cochlea is responsible for converting sound vibrations into electrical signals for the brain to interpret. The semicircular canals are not involved in transmitting sound but are responsible for balance and orientation. The eustachian tube's function is to help equalize pressure in the middle ear, not to transmit sound vibrations.

4. What scientific term encompasses a permanent alteration in the DNA sequence?

• A. Trait
• B. Mutation
• C. Allele
• D. Variation

Correct answer: B

Rationale: A) Trait: A trait is a characteristic or feature of an organism that is determined by its genes. B) Mutation: A mutation is a permanent alteration in the DNA sequence that can result from errors during DNA replication, exposure to mutagens, or other factors. C) Allele: An allele is a variant form of a gene that can result in different traits or characteristics. D) Variation: Variation refers to the differences in traits or characteristics among individuals of the same species, which can be influenced by genetic and environmental factors. In this context, the term that specifically refers to a permanent alteration in the DNA sequence is "mutation."

5. How many moles of oxygen are required to completely react with 5 moles of propane (C3H8) in the combustion reaction?

• A. 5 moles
• B. 10 moles
• C. 15 moles
• D. 20 moles

Correct answer: C

Rationale: In the balanced chemical equation for the combustion of propane (C3H8): C3H8 + 5O2 → 3CO2 + 4H2O, 1 mole of propane (C3H8) reacts with 5 moles of oxygen (O2). To determine the moles of oxygen required to react with 5 moles of propane, we use the molar ratio: 5 moles propane x 5 moles oxygen / 1 mole propane = 25 moles oxygen. However, since the question specifically asks for the moles of oxygen needed to react with 5 moles of propane, the correct answer is 15 moles of oxygen. Choice A, 5 moles, is incorrect because this is the amount of propane provided, not the oxygen required. Choice B, 10 moles, is incorrect as it does not correspond to the molar ratio in the balanced equation. Choice D, 20 moles, is incorrect as it is not in line with the stoichiometry of the reaction.

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