Nursing Elites

1. When ice melts, it undergoes a...

• A. Chemical change
• B. Physical change
• C. Nuclear change
• D. Radioactive decay

Correct answer: B

Rationale: When ice melts, it undergoes a physical change, transitioning from a solid state to a liquid state. This change does not involve altering the chemical composition of the ice, making it a physical change rather than a chemical change, nuclear change, or radioactive decay. Choice A, 'Chemical change,' is incorrect because a chemical change involves a rearrangement of atoms resulting in new substances. Choice C, 'Nuclear change,' is incorrect as it refers to changes in the nucleus of an atom, not the phase transition of ice. Choice D, 'Radioactive decay,' is incorrect as it involves the spontaneous disintegration of an unstable atomic nucleus, which is not the process occurring when ice melts.

2. What is the correct way to represent 8,600,000,000,000 in scientific notation with two significant figures?

• A. 8.6 x 10^12
• B. 8.6 x 10^-12
• C. 8.6 x 10^11
• D. 8.60 x 10^12

Correct answer: A

Rationale: The correct way to represent 8,600,000,000,000 in scientific notation with two significant figures is 8.6 x 10^12. Scientific notation involves expressing a number as a decimal (with one non-zero digit before the decimal point) multiplied by a power of 10. In this case, 8,600,000,000,000 is correctly written as 8.6 x 10^12 to maintain two significant figures and the appropriate magnitude. Choice B (8.6 x 10^-12) is incorrect as it represents a very small number due to the negative exponent. Choice C (8.6 x 10^11) is incorrect as it does not account for the magnitude of the original number. Choice D (8.60 x 10^12) is incorrect because it unnecessarily adds a zero after the decimal point, which is not warranted by the original number's precision.

3. The innate immune system provides a non-specific first line of defense. What are some physical barriers that contribute to the innate immune system?

• A. Antibodies
• B. Phagocytes
• C. Skin and mucous membranes
• D. Memory B cells

Correct answer: C

Rationale: Physical barriers such as the skin and mucous membranes are crucial components of the innate immune system's first line of defense. These barriers act as physical obstacles that prevent pathogens from entering the body. Antibodies (option A) are produced by the adaptive immune system in response to specific pathogens and do not serve as physical barriers. Phagocytes (option B) are cells that engulf and digest pathogens, playing a role in the innate immune response but not as physical barriers. Memory B cells (option D) are part of the adaptive immune system and aid in mounting a faster and more effective immune response upon subsequent exposure to a specific pathogen, but they are not physical barriers against initial pathogen entry.

4. Which type of energy is associated with the random motion of particles in a substance?

• A. Potential energy
• B. Mechanical energy
• C. Thermal energy
• D. Chemical energy

Correct answer: C

Rationale: Thermal energy is the correct answer as it is associated with the random motion of particles in a substance. When particles move randomly, they generate heat energy, which is a form of thermal energy. Potential energy is stored energy that can be converted into other forms when released, such as kinetic energy. Mechanical energy is the sum of potential and kinetic energy in an object, which is not directly related to the random motion of particles. Chemical energy is energy stored in the bonds of chemical compounds and is not specifically related to the motion of particles.

5. What is the role of the pancreas in the digestive system?

• A. To store bile
• B. To secrete digestive enzymes
• C. To digest proteins
• D. To absorb nutrients

Correct answer: B

Rationale: The correct answer is B: 'To secrete digestive enzymes.' The pancreas plays a crucial role in the digestive system by secreting digestive enzymes that aid in breaking down food in the small intestine. These enzymes help in the digestion of carbohydrates, fats, and proteins, facilitating the absorption of nutrients from the digested food. Choice A is incorrect because the pancreas is not responsible for storing bile; the gallbladder stores bile. Choice C is incorrect because the pancreas secretes enzymes for protein digestion but does not digest proteins itself. Choice D is incorrect as the absorption of nutrients primarily occurs in the small intestine, not in the pancreas.

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