Nursing Elites

1. How many electrons are typically found in each shell of a neutral aluminum atom with 13 electrons in its electron cloud?

• A. 6 in the first shell, 7 in the second shell
• B. 2 in the first shell, 11 in the second shell
• C. 2 in the first shell, 8 in the second shell, 3 in the third shell
• D. 3 in the first shell, 5 in the second shell, 5 in the third shell

Correct answer: C

Rationale: In a neutral aluminum atom with 13 electrons, the electron distribution typically follows the electron shell filling order based on the Aufbau principle. The first shell can hold a maximum of 2 electrons, the second shell can hold up to 8 electrons, and the third shell can hold up to 8 electrons as well. Therefore, the distribution would be 2 electrons in the first shell, 8 electrons in the second shell, and 3 electrons in the third shell, totaling 13 electrons. Choice A is incorrect as it exceeds the maximum number of electrons the shells can hold. Choice B is incorrect as it does not distribute the electrons correctly among the shells. Choice D is incorrect as it also does not distribute the electrons correctly among the shells.

2. A 10 kg box rests on a frictionless surface. A horizontal force of 20 N is applied to the box. What is the box's acceleration?

• A. 0.5 m/s²
• B. 1 m/s²
• C. 2 m/s²
• D. 10 m/s²

Correct answer: B

Rationale: The acceleration of an object is given by the formula \(a = \frac{F}{m}\), where \(F\) is the net force acting on the object and \(m\) is the mass of the object. In this case, the net force acting on the box is 20 N, and the mass of the box is 10 kg. Plugging these values into the formula, we get \(a = \frac{20}{10} = 2\) m/s².

3. What is the difference between a real image and a virtual image formed by a lens?

• A. Real images can be projected onto a screen, while virtual images cannot.
• B. Real images are always upright, while virtual images can be inverted.
• C. Real images are formed by converging lenses, while virtual images are formed by diverging lenses.
• D. All of the above are true.

Correct answer: A

Rationale: The correct answer is A. Real images can be projected onto a screen because they are formed by the actual convergence of light rays, while virtual images cannot be projected onto a screen as they appear to diverge from a point behind the lens. Real and virtual images do not have a consistent orientation (upright or inverted), so option B is incorrect. Real images are formed by both converging and diverging lenses depending on the specific scenario, so option C is not a definitive distinction. Option D is incorrect as not all the statements are true. Therefore, the only accurate general distinction between real and virtual images is that real images can be projected onto a screen, while virtual images cannot.

4. Which part of the digestive system is responsible for absorbing nutrients?

• A. Esophagus
• B. Stomach
• C. Small intestine
• D. Large intestine

Correct answer: C

Rationale: The small intestine is the correct answer because it is the primary site for nutrient absorption in the digestive system. It contains specialized structures such as villi and microvilli that maximize the absorption of nutrients from digested food. The esophagus is responsible for transporting food from the mouth to the stomach; the stomach primarily aids in digestion by secreting enzymes and acids; and the large intestine mainly absorbs water and electrolytes from the remaining indigestible food matter. Therefore, the small intestine plays a crucial role in absorbing essential nutrients for the body's functions, making it the correct choice in this context.

5. Unlike the circulatory system, the lymphatic system does not have a pump. How does lymph move through the lymphatic vessels?

• A. By the pumping action of the heart
• B. Due to muscle contractions and breathing movements
• C. Through one-way valves within the vessels
• D. All of the above

Correct answer: C

Rationale: Lymph moves through the lymphatic vessels primarily due to muscle contractions and breathing movements and also with the help of one-way valves within the vessels. The lymphatic system lacks a central pump like the heart; hence, it relies on the contraction of surrounding muscles and breathing movements to propel lymph fluid. One-way valves within the lymphatic vessels prevent backflow and ensure the unidirectional flow of lymph. Option A is incorrect as the lymphatic system does not rely on the pumping action of the heart. Option D is incorrect as the correct answer is the combination of muscle contractions, breathing movements, and one-way valves, not all the options provided.

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