Nursing Elites

1. When is a solution formed?

• A. One substance dissolves in another
• B. Two or more substances react chemically
• C. A solid changes to a liquid
• D. None of the above

Correct answer: A

Rationale: A solution is formed when one substance dissolves in another. This process creates a homogeneous mixture where the solute is dispersed in the solvent, resulting in a uniform composition throughout the mixture. Choice B is incorrect because chemical reactions involve the transformation of substances into new compounds, not the formation of solutions. Choice C is incorrect as it describes a physical change from a solid to a liquid, not the formation of a solution. Choice D is incorrect as one substance dissolving in another is the defining characteristic of a solution.

2. What is the approximate composition of blood?

• A. 45% plasma, 55% formed elements
• B. 55% plasma, 45% formed elements
• C. 55% water, 45% blood cells
• D. 45% water, 55% plasma

Correct answer: B

Rationale: Blood is composed of approximately 55% plasma (mostly water with proteins, electrolytes, and nutrients) and 45% formed elements (red blood cells, white blood cells, and platelets). Choice B is the correct answer. Choice A is incorrect as it reverses the percentages. Choice C is incorrect because it incorrectly states that blood cells make up 45% of blood, while they are part of the formed elements along with platelets. Choice D is incorrect as it suggests that water makes up 45% of blood, which is not accurate.

3. Which statement below best describes the process of condensation?

• A. Condensation is the process of changing from a gas to a liquid.
• B. Condensation is the process of changing from a liquid to a gas.
• C. Condensation is the process of changing from a solid to a liquid.
• D. Condensation is the process of changing from a solid to a gas.

Correct answer: A

Rationale: The correct answer is A: 'Condensation is the process of changing from a gas to a liquid.' Condensation occurs when a gas cools and transforms into a liquid state. For example, when water vapor in the air cools and forms droplets, it is an example of condensation. This process is commonly observed in the formation of clouds or dew on grass in the early morning. Choice B is incorrect because it describes the process of vaporization rather than condensation. Choice C is incorrect as it refers to the process of melting. Choice D is incorrect as it describes sublimation, which is the transition from a solid to a gas without passing through the liquid phase.

4. What is the diastole cycle in the heart?

• A. Relaxation of the heart
• B. Contraction of the heart
• C. Pulse rate of the heart
• D. Blood circulation

Correct answer: A

Rationale: The diastole cycle in the heart refers to the relaxation phase, where the heart chambers relax and fill with blood. This phase is crucial for the heart to refill and prepare for the next contraction (systole), which pumps blood out of the heart. Therefore, the correct answer is choice A, 'Relaxation of the heart.' Choices B, C, and D are incorrect in the context of cardiac physiology. Choice B, 'Contraction of the heart,' refers to systole, the phase of heart contraction. Choice C, 'Pulse rate of the heart,' is related to the number of heartbeats per minute, not the diastole cycle specifically. Choice D, 'Blood circulation,' is a broader term that encompasses the entire circulatory system rather than focusing on the heart's specific relaxation phase.

5. How does friction affect motion?

• A. Friction increases speed
• B. Friction decreases speed
• C. Friction has no impact on speed
• D. Friction causes objects to float

Correct answer: B

Rationale: Friction is a force that opposes motion when two surfaces are in contact. It acts in the opposite direction to the direction of motion, causing objects to slow down or come to a stop. Therefore, friction decreases speed rather than increasing it. Choice A is incorrect as friction does not increase speed but rather hinders it. Choice C is incorrect because friction does have an impact on speed by slowing down objects. Choice D is incorrect as friction's effect is not making objects float but rather causing resistance to motion.

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