Nursing Elites

1. What is the atomic number of an atom?

• A. The number of protons in an atom
• B. The number of neutrons in an atom
• C. The number of electrons in an atom
• D. The sum of protons and neutrons

Correct answer: A

Rationale: The correct answer is A: The atomic number of an atom is the number of protons in its nucleus. This number uniquely identifies the element, as each element has a distinct number of protons. Neutrons and electrons play roles in the atom's structure and stability, but the atomic number specifically refers to the number of protons. Choice B (The number of neutrons in an atom) is incorrect because the atomic number does not include neutrons; it only represents the number of protons. Choice C (The number of electrons in an atom) is incorrect because the atomic number is not related to the number of electrons, which can vary in different atomic configurations. Choice D (The sum of protons and neutrons) is incorrect because it refers to the mass number of an atom, which is the total number of protons and neutrons in the nucleus, not just the protons.

2. Which of the following chambers of the heart receives blood returning from the lungs during pulmonary circulation?

• A. left atrium
• B. right atrium
• C. left ventricle
• D. right ventricle

Correct answer: A

Rationale: The correct answer is A, the left atrium. During pulmonary circulation, oxygenated blood returns from the lungs to the heart and enters the left atrium through the pulmonary veins. The left atrium then contracts, pushing this oxygen-rich blood into the left ventricle. The left ventricle subsequently pumps this oxygenated blood out to the rest of the body through the aorta. Choices B, C, and D are incorrect because the right atrium receives deoxygenated blood from the body, the left ventricle receives oxygenated blood from the left atrium, and the right ventricle pumps deoxygenated blood to the lungs for oxygenation, respectively.

3. Which structure in the digestive system absorbs the most nutrients?

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

Correct answer: B

Rationale: The small intestine is the primary site where the absorption of nutrients from digested food occurs. Its large surface area, specialized cells, and villi play key roles in maximizing nutrient absorption, making it the structure in the digestive system that absorbs the most nutrients. The stomach's main function is to break down food with acid and enzymes, not absorb nutrients. The large intestine primarily absorbs water and electrolytes, not nutrients. The esophagus is a muscular tube that connects the throat with the stomach and does not play a role in nutrient absorption.

4. What is the relationship between mass and weight on Earth's surface?

• A. Mass and weight are equal
• B. Mass is greater than weight
• C. Weight is greater than mass
• D. Mass and weight are not related

Correct answer: C

Rationale: The correct answer is C: Weight is greater than mass. Mass is a measure of the amount of matter in an object, while weight is the force of gravity acting on that object. On Earth's surface, weight is greater than mass because gravity pulls objects towards the center of the Earth, resulting in a force that we perceive as weight. Choice A is incorrect because mass and weight are not equal; weight is a force, while mass is a measure of the amount of matter. Choice B is incorrect because mass is not greater than weight; weight is the force exerted due to gravity. Choice D is incorrect as mass and weight are related; weight is dependent on mass and the gravitational force acting on the object.

5. How does the body maintain a relatively constant blood pH level, even with changes in blood carbon dioxide concentration?

• A. Cellular respiration
• B. Gas exchange
• C. Buffering system
• D. Deoxygenation

Correct answer: C

Rationale: The correct answer is C: Buffering system. The buffering system is responsible for maintaining a relatively constant blood pH level by minimizing changes in pH when acids or bases are added to the blood. This system consists of chemical compounds that can donate or accept protons to help stabilize the pH. Choice A, Cellular respiration, and Choice B, Gas exchange, are processes involved in gas exchange within the body, not specifically related to maintaining blood pH. Choice D, Deoxygenation, refers to the removal of oxygen from a substance and is not directly related to the regulation of blood pH.

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