Nursing Elites

1. What is the balanced chemical equation for the reaction between sodium and chlorine to form sodium chloride?

• A. Na + Cl2 -> NaCl
• B. 2Na + Cl2 -> 2NaCl
• C. Na2 + Cl -> 2NaCl
• D. Na + 2Cl -> NaCl2

Correct answer: B

Rationale: In a balanced chemical equation, the number of atoms of each element must be the same on both sides of the equation. When sodium (Na) reacts with chlorine (Cl2) to form sodium chloride (NaCl), we need to ensure the equation is balanced. There are 2 chlorine atoms in Cl2; hence, we need 2 sodium atoms on the left side to balance it. Therefore, the balanced chemical equation is 2Na + Cl2 -> 2NaCl. Choice A is incorrect because it does not have the correct coefficients to balance the equation. Choice C is incorrect as it incorrectly represents the formula of sodium. Choice D is incorrect as it forms NaCl2, which is not the correct compound formed in this reaction.

2. A person wakes up with a fever. The body begins its response to locate the origin of the problem and fix it. What type of feedback mechanism is this?

• A. Equal
• B. Negative
• C. Neutral
• D. Positive

Correct answer: B

Rationale: This scenario describes a negative feedback mechanism. When the body detects a fever, it initiates responses to lower the temperature back to normal levels. Negative feedback mechanisms work to counteract changes and maintain homeostasis in the body. Choice A ('Equal') is incorrect as feedback mechanisms aim to restore balance, not maintain an equal state. Choice C ('Neutral') is incorrect as it does not describe the corrective nature of negative feedback. Choice D ('Positive') is incorrect as it would amplify the fever rather than regulate it.

3. In the electron cloud model, electrons occupy specific energy levels around the nucleus with varying probabilities. This model depicts electrons existing in distinct energy levels, not fixed orbits, with probabilities of finding them in specific regions.

• A. 2 protons and 6 neutrons
• B. 2 filled s orbitals and 6 filled p orbitals
• C. 2s orbitals with 2 and 6 electrons, respectively
• D. 4 filled electron shells

Correct answer: C

Rationale: The electron cloud model describes electrons existing in distinct energy levels, not fixed orbits. Option C correctly describes the electron configuration of an atom with 2s orbitals containing 2 electrons and 6 electrons in the 2p orbitals. This configuration aligns with the electron cloud model where electrons are found in specific energy levels with varying probabilities. Options A, B, and D do not accurately represent the electron cloud model.

4. Calcitonin, a hormone that helps regulate calcium levels, is produced by the:

• A. Thyroid gland
• B. Parathyroid gland
• C. Thymus gland
• D. Adrenal gland

Correct answer: A

Rationale: Calcitonin is a hormone produced by the thyroid gland. It helps regulate calcium levels in the body by inhibiting the breakdown of bone and promoting calcium excretion by the kidneys. The parathyroid gland produces parathyroid hormone (PTH), which works in opposition to calcitonin to regulate calcium levels. The thymus gland is involved in the development of the immune system, and the adrenal gland produces hormones such as cortisol and adrenaline. Therefore, the correct answer is the thyroid gland as it specifically secretes calcitonin for calcium regulation.

5. What is the protective fluid that surrounds the brain and spinal cord?

• A. Blood
• B. Cerebrospinal fluid
• C. Myelin sheath
• D. Insulin

Correct answer: B

Rationale: Cerebrospinal fluid is the protective fluid that surrounds the brain and spinal cord. It acts as a cushion to protect these vital organs from injury and provides nutrients and removes waste products. Blood, myelin sheath, and insulin do not serve as the protective fluid surrounding the brain and spinal cord. Blood carries nutrients and oxygen to cells, myelin sheath is a protective covering of nerve fibers, and insulin is a hormone involved in regulating blood sugar levels.

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