Nursing Elites

1. What lab equipment would most likely be used to precisely measure the volume of a liquid solution?

• A. Flask
• B. Triple beam balance
• C. Graduated cylinder
• D. Test tube

Correct answer: C

Rationale: A graduated cylinder is the most suitable lab equipment for precisely measuring the volume of a liquid solution. Graduated cylinders are designed with calibrated markings that allow for accurate volume measurements of liquids. The other choices are not appropriate for measuring liquid volume: Flasks are used for mixing or storing liquids, triple beam balances are used for measuring mass, and test tubes are typically used for holding small amounts of substances during experiments.

2. How many grams of solid CaCO3 are needed to make 600 mL of a 35 M solution? The atomic masses for the elements are as follows: Ca = 40.1 g/mol; C = 12.01 g/mol; O = 16.00 g/mol.

• A. 18.3 g
• B. 19.7 g
• C. 21.0 g
• D. 24.2 g

Correct answer: B

Rationale: 1. First, calculate the molar mass of CaCO3 by adding the atomic masses of Ca, C, and 3 O atoms: 40.1 + 12.01 + (3 * 16.00) = 100.13 g/mol. 2. Calculate the number of moles in 600 mL of a 35 M solution: 600 mL * 35 mol/L = 21,000 mmol. 3. Convert moles to grams using the molar mass of CaCO3: 21,000 mmol * (100.13 g/mol / 1000 mmol/mol) = 2,102.73 g. 4. Therefore, you would need 19.7 g of solid CaCO3 to make 600 mL of a 35 M solution.

3. What type of macromolecule is hemoglobin?

• A. Carbohydrate
• B. Lipid
• C. Protein
• D. Nucleic acid

Correct answer: C

Rationale: The correct answer is C: Protein. Hemoglobin is a protein responsible for carrying oxygen in the blood. Proteins are macromolecules made up of amino acids and play a vital role in various biological functions, including the transportation of molecules like oxygen. Choices A, B, and D are incorrect because carbohydrates, lipids, and nucleic acids are different types of macromolecules that have distinct structures and functions. Carbohydrates are mainly involved in energy storage and structural support, lipids are essential for energy storage and cell membrane structure, and nucleic acids are responsible for storing and transmitting genetic information.

4. 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 of the sample to decay.
• C. The rate at which new isotopes are created.
• D. The energy released during decay.

Correct answer: A

Rationale: The half-life of a radioactive isotope is the time it takes for half of the initial sample to decay. After one half-life, half of the radioactive atoms have decayed. The decay rate, however, refers to the rate at which radioactive atoms decay, which is not directly related to the half-life. Choice B is incorrect because it does not correctly define the half-life. Choice C is incorrect as it refers to the creation of new isotopes, not the decay process. Choice D is incorrect as it describes the energy released during decay, which is not the same as the concept of half-life.

5. Why can optical fibers transmit light signals around bends?

• A. Reflection
• B. Refraction
• C. Diffraction
• D. Polarization

Correct answer: B

Rationale: Optical fibers can transmit light signals around bends primarily due to refraction. Refraction is the bending of light as it passes from one medium to another, such as from air to glass in an optical fiber. This bending allows the light signals to travel through the fiber even around bends, making optical fibers an efficient means of transmitting light signals over long distances. Reflection (Choice A) occurs when light bounces off a surface, which is not the primary mechanism allowing light to travel around bends in optical fibers. Diffraction (Choice C) refers to the bending of light waves around obstacles or openings, but it is not the main reason light signals can traverse bends in optical fibers. Polarization (Choice D) is the orientation of light waves in a specific plane, but it does not play a significant role in enabling light to navigate bends in optical fibers.

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