Nursing Elites

1. Which of the following substances is an example of an acidic gas?

• A. Nitrogen (Nâ‚‚)
• B. Carbon dioxide (COâ‚‚)
• C. Sulfur dioxide (SOâ‚‚)
• D. Oxygen (Oâ‚‚)

Correct answer: C

Rationale: The correct answer is C, Sulfur dioxide (SOâ‚‚). Sulfur dioxide is an acidic gas because when dissolved in water, it forms sulfurous acid, which imparts acidic properties. Nitrogen (Nâ‚‚), carbon dioxide (COâ‚‚), and oxygen (Oâ‚‚) are not considered acidic gases. Nitrogen is a neutral gas, carbon dioxide forms a weakly acidic solution when dissolved in water, and oxygen is a neutral gas.

2. How can you predict the charge of an ion formed by an element based on its position on the periodic table?

• A. Look for elements with similar atomic weights
• B. Identify the group number, which often indicates the typical ionic charge
• C. Identify the period number to determine the ionic charge
• D. Analyze the element's position within the group

Correct answer: B

Rationale: The group number of an element on the periodic table often indicates the typical ionic charge it will form. Elements in the same group tend to have similar chemical properties, including the tendency to gain or lose electrons to achieve a stable electron configuration. This predictable pattern allows us to anticipate the charge of an ion formed by an element based on its position in the periodic table. Choices A, C, and D are incorrect because predicting the charge of an ion is primarily based on the element's group number, which reflects its valence electrons and typical ionic charge. Atomic weight (Choice A) and period number (Choice C) do not directly correlate with the ionic charge prediction, and analyzing the element's position within the group (Choice D) is less relevant than identifying the group number itself.

3. An uncharged atom has an electron configuration of 1s² 2s² 2p⁶ 3s² and a mass number of 14. How many protons does it have?

• A. 14
• B. 6
• C. 8
• D. 12

Correct answer: B

Rationale: The number of protons in an atom is determined by the atomic number, which is equal to the number of protons in the nucleus. The electron configuration given corresponds to carbon (C) with 6 protons. The atomic number of an element is the same as the number of protons in its nucleus, so in this case, the atom has 6 protons. Choices A, C, and D are incorrect because they do not correspond to the correct number of protons for an atom with the given electron configuration and mass number. Therefore, option B, 6 protons, is the correct answer.

4. Memory B cells and memory T cells are crucial for immunological memory. How does immunological memory enhance the immune response upon re-exposure to a pathogen?

• A. It increases the production of the same ineffective antibodies.
• B. It allows for a quicker and more robust immune response.
• C. It suppresses the immune system to prevent overreaction.
• D. It triggers a completely different immune response.

Correct answer: B

Rationale: Immunological memory enhances the immune response upon re-exposure to a pathogen by allowing for a quicker and more robust immune response. Memory B cells and memory T cells are primed to recognize the pathogen quickly and mount a faster and more effective response, leading to a more efficient clearance of the pathogen. Choice A is incorrect because immunological memory does not increase the production of ineffective antibodies but rather promotes the production of specific antibodies that are effective against the pathogen. Choice C is incorrect as immunological memory does not suppress the immune system; instead, it enhances the response. Choice D is incorrect because immunological memory leads to a recall of the specific immune response mounted during the initial exposure, not a completely different response.

5. What are the moon-shaped white structures at the base of fingernails called?

• A. Lunulae
• B. Cuticle
• C. Hyponychium
• D. Matrix

Correct answer: A

Rationale: The correct answer is A: Lunulae. The moon-shaped white structures at the base of fingernails are known as lunulae. They are most prominent on the thumb and are situated at the base of the nail matrix. The lunula is the visible part of the nail matrix, which is responsible for generating new nail cells. Choice B, Cuticle, is incorrect as it refers to the thin layer of skin at the base of the nail plate. Choice C, Hyponychium, is incorrect as it is the skin that lies beneath the free edge of the nail. Choice D, Matrix, is incorrect as it is the area where the nail is formed, located under the cuticle.

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