Nursing Elites

1. Why do Neon (Ne) and Helium (He) belong to Group 18 (Noble Gases)?

• A. Electromagnetism
• B. Gravity
• C. Strong nuclear force
• D. Weak nuclear force

Correct answer: A

Rationale: Neon (Ne) and Helium (He) belong to Group 18 (Noble Gases) because they have complete and stable outer electron shells. The stability of these outer electron shells is due to the balance of attractive forces between the positively charged protons in the nucleus and the negatively charged electrons in the outer shell. This balance is maintained by the electromagnetic force, which is responsible for holding atoms together and determining their chemical properties. Gravity (Choice B) is a force of attraction between objects with mass and is not responsible for the stability of electron shells. The strong nuclear force (Choice C) and weak nuclear force (Choice D) are forces that act within the nucleus of an atom and are not directly related to the stability of outer electron shells in determining an element's group in the periodic table.

2. Why are elements in Group 18 (Noble gases) generally unreactive?

• A. They have high atomic masses
• B. They lack valence electrons
• C. Their outermost electron shells are completely filled
• D. They exist as single atoms, not molecules

Correct answer: C

Rationale: Elements in Group 18 (Noble gases) are generally unreactive because their outermost electron shells are completely filled. This results in high stability and low reactivity since they have achieved a full valence shell configuration, making them less likely to gain, lose, or share electrons with other atoms. The full valence shell configuration leads to a minimal tendency for these elements to form chemical bonds, hence exhibiting low reactivity. Choices A, B, and D are incorrect because high atomic masses, lack of valence electrons, and existing as single atoms do not directly contribute to the unreactivity of noble gases. It is the full valence shell configuration that is the primary reason for their inert nature.

3. What are the three regions of the small intestine?

• A. Duodenum, ileum, jejunum
• B. Cecum, ileum, jejunum
• C. Duodenum, jejunum, ileum
• D. Duodenum, jejunum, colon

Correct answer: C

Rationale: The correct answer is C: Duodenum, jejunum, ileum. The small intestine is divided into three regions: the duodenum, jejunum, and ileum. The duodenum is the initial segment where most chemical digestion takes place. The jejunum and ileum follow the duodenum and are primarily responsible for nutrient absorption. Choice A is incorrect because the order is incorrect. Choice B is incorrect because the cecum is part of the large intestine, not the small intestine. Choice D is incorrect because the colon is part of the large intestine, not the small intestine.

4. What is the primary function of tight junctions, specialized regions between animal cells?

• A. Communication between cells
• B. Anchorage between cells
• C. Selective passage of materials
• D. All of the above

Correct answer: C

Rationale: The correct answer is C: Selective passage of materials. Tight junctions act as specialized structures between animal cells that create a barrier to the passage of materials. Their primary function is to prevent the leakage of extracellular fluid and control the selective passage of molecules between cells. This selective control is crucial in regulating the movement of substances across cell layers. Tight junctions do not directly facilitate communication between cells or provide anchorage between cells, as their main role is to regulate the passage of materials. Choices A and B are incorrect as tight junctions do not primarily serve for communication or anchorage between cells.

5. With which genotype would the recessive phenotype appear if the dominant allele is marked with 'A' and the recessive allele is marked with 'a'?

• A. AA
• B. aa
• C. Aa
• D. aA

Correct answer: B

Rationale: The recessive phenotype appears when an individual has two copies of the recessive allele. In this case, the recessive allele is marked with 'a.' Therefore, the genotype 'aa' would display the recessive phenotype as both alleles are recessive. Choice A (AA) has two dominant alleles, choice C (Aa) has one dominant and one recessive allele, and choice D (aA) represents the same genotype as Aa due to the principle of allele dominance.

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