Nursing Elites

1. What properties distinguish laser light from typical light sources?

• A. Enhanced brightness only
• B. Monochromatic nature (single color) and coherence (synchronized waves)
• C. Increased velocity
• D. Limited visibility to the human eye

Correct answer: B

Rationale: Laser light differs from typical light sources due to its monochromatic nature (single color) and coherence (synchronized waves). This means that laser light consists of a single wavelength and synchronized waves, unlike typical light sources that emit a range of wavelengths and are incoherent. The monochromatic nature of laser light allows it to be of a single color, while coherence ensures that the waves are synchronized. These unique properties of laser light make it valuable for a wide range of applications in fields such as medicine, industry, and research. Choices A, C, and D are incorrect because laser light's distinguishing features are not related to enhanced brightness, increased velocity, or limited visibility to the human eye. Instead, it is the monochromatic nature and coherence that set laser light apart from typical light sources.

2. Which element has the highest melting point of any element?

• A. Tungsten
• B. Iron
• C. Platinum
• D. Carbon

Correct answer: D

Rationale: Among the choices provided, carbon, in the form of diamond, has the highest melting point of any element. Diamond's strong covalent bonds between carbon atoms make it incredibly resistant to heat and pressure, giving it the highest melting point compared to tungsten, iron, and platinum. Tungsten is known for its high melting point among metals but not as high as carbon. Iron and platinum have lower melting points compared to carbon, making them incorrect choices in this context.

3. What is the main difference between white and brown adipose tissue?

• A. Location only
• B. Function and energy metabolism
• C. Color only
• D. Both white and brown have the same function

Correct answer: B

Rationale: The main difference between white and brown adipose tissue lies in their function and energy metabolism. White adipose tissue is primarily involved in energy storage, while brown adipose tissue is specialized for energy expenditure and thermogenesis. This functional disparity is the key dissimilarity between white and brown adipose tissue, rather than just their location or color. Choice A is incorrect because the difference is not only in location but also in function. Choice C is incorrect as color is not the defining factor in their distinction. Choice D is incorrect as white and brown adipose tissues serve different functions in the body.

4. The chemical equation below is unbalanced. When it is properly balanced, how many molecules of carbon dioxide (CO2) are produced for each molecule of propane (C3H8) in the reaction? 3C3H8 + 5O2 → 3CO2 + 4H2O

• A. One Half.
• B. Two.
• C. Three.
• D. Five.

Correct answer: B

Rationale: The balanced chemical equation for the combustion of propane is: 3C3H8 + 5O2 → 3CO2 + 4H2O. This equation shows that for every 3 molecules of propane (C3H8) consumed, 3 molecules of carbon dioxide (CO2) are produced. Therefore, when properly balanced, 3CO2 are produced for each molecule of propane used. Thus, the correct answer is B: Two. Choices A, C, and D are incorrect because they do not reflect the correct stoichiometry as determined by the balanced equation.

5. Which of the following units is used to express concentration as a mass of solute per unit volume of solution?

• A. Molality (m)
• B. Molarity (M)
• C. Weight percent (%)
• D. Parts per million (ppm)

Correct answer: A

Rationale: Molality (m) is the unit used to express concentration as a mass of solute per unit volume of solution. It is calculated by dividing the mass of solute in grams by the mass of the solvent in kilograms. Molality is preferred over molarity when there are large temperature variations as it is temperature-independent, making it a more accurate measure of concentration. Molarity (B) is the unit used to express concentration as moles of solute per liter of solution, weight percent (C) is the mass of solute per 100 parts of the total mass of the solution, and parts per million (D) is used to express very small concentrations where 1 ppm is equivalent to 1 mg of solute per liter of solution.

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