Nursing Elites

1. In a covalent bond, the shared electrons:

• A. Are completely transferred to one atom.
• B. Spend more time closer to the more electronegative atom.
• C. Remain equidistant between the two atoms.
• D. Do not influence the bond strength.

Correct answer: B

Rationale: In a covalent bond, the shared electrons spend more time closer to the more electronegative atom. Electronegativity is the ability of an atom to attract electrons in a chemical bond. The more electronegative atom exerts a stronger pull on the shared electrons, causing them to be closer to that atom. Choice A is incorrect because in a covalent bond, electrons are shared, not completely transferred. Choice C is incorrect as the shared electrons are not equidistant but are closer to one atom due to electronegativity differences. Choice D is incorrect because shared electrons play a significant role in determining the bond strength by the strength of the bond formed through electron sharing.

2. As a water wave approaches a shallow beach, what happens to its speed, wavelength, and frequency?

• A. Speed increases, wavelength decreases, frequency increases.
• B. Speed decreases, wavelength decreases, frequency remains the same.
• C. Speed increases, wavelength increases, frequency decreases.
• D. Speed, wavelength, and frequency remain the same.

Correct answer: B

Rationale: As a water wave approaches a shallow beach, the speed of the wave decreases due to the change in medium from deep to shallow water. According to the wave equation (speed = frequency x wavelength), if the speed decreases and the frequency remains the same, the wavelength must also decrease to maintain the equation balanced. This phenomenon occurs due to the wavefronts being slowed down by the shallower water, causing the wavelength to decrease while the frequency remains constant. Choice A is incorrect as the speed of the wave decreases in shallow water. Choice C is incorrect because the speed increases in deep water, not in shallow water. Choice D is incorrect as all the wave characteristics change when moving from deep to shallow water.

3. What is the momentum of a car with a mass of 1500 kg moving at a speed of 20 m/s?

• A. 30,000 kg m/s
• B. 1500 kg m/s
• C. 20 kg m/s
• D. Momentum cannot be determined without knowing the direction of motion.

Correct answer: A

Rationale: The momentum of an object is calculated by multiplying its mass by its velocity. In this case, the momentum of the car can be determined using the formula momentum = mass x velocity. Substituting the given values, momentum = 1500 kg x 20 m/s = 30,000 kg m/s. Therefore, the correct answer is A, 30,000 kg m/s. Choice B (1500 kg m/s) is incorrect because that value represents the mass of the car, not its momentum. Choice C (20 kg m/s) is incorrect as it only represents the speed of the car, not its momentum. Choice D (Momentum cannot be determined without knowing the direction of motion) is incorrect because momentum is a vector quantity and can be determined using magnitude and direction, but in this case, only the magnitude is required.

4. What is the primary function of the placenta during pregnancy?

• A. Produce insulin
• B. Facilitate gas exchange between mother and fetus
• C. Excrete waste products from the fetus
• D. All of the above

Correct answer: B

Rationale: The primary function of the placenta during pregnancy is to facilitate the exchange of oxygen and carbon dioxide between the mother and the fetus. This ensures that the fetus receives oxygen and eliminates carbon dioxide, supporting its growth and development. While the placenta also allows for the transfer of nutrients and waste products between the mother and the fetus, its main role is to ensure proper gas exchange. Therefore, choices A, C, and D are incorrect as the primary role of the placenta is not to produce insulin or excrete waste products from the fetus. Selecting the correct answer, choice B, highlights the crucial role of the placenta in providing oxygen to the fetus and removing carbon dioxide, which are essential for fetal well-being and development.

5. What happens to the frequency of a wave when its wavelength is doubled, assuming the speed remains constant?

• A. Frequency remains the same.
• B. Frequency is halved.
• C. Frequency is doubled.
• D. Frequency information is insufficient to determine.

Correct answer: B

Rationale: When the wavelength of a wave is doubled, and the speed of the wave remains constant, the frequency of the wave is halved. This relationship is governed by the equation speed = frequency x wavelength. Therefore, if the wavelength is doubled while the speed remains constant, the frequency must be halved to maintain a constant speed. Choice A is incorrect because frequency and wavelength are inversely proportional when speed is constant. Choice C is incorrect as doubling the wavelength does not result in a doubled frequency. Choice D is incorrect as the relationship between frequency, wavelength, and speed can be determined using the given information.

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