Nursing Elites

1. Which statement accurately describes the periodic trends in atomic radius?

• A. Increases down a group and decreases across a period
• B. Decreases down a group and increases across a period
• C. Remains constant throughout the table
• D. Fluctuates unpredictably based on individual elements

Correct answer: A

Rationale: The correct statement is that atomic radius increases down a group and decreases across a period. When moving down a group, additional electron shells increase the distance from the nucleus, leading to larger atomic radii. On the other hand, when moving across a period, the number of electron shells remains constant, but the increasing nuclear charge pulls electrons closer, resulting in smaller radii. Choice B is incorrect because atomic radius does not decrease down a group and increase across a period. Choice C is incorrect because atomic radius does not remain constant; it exhibits specific trends. Choice D is incorrect because atomic radius follows predictable trends based on the periodic table structure, rather than fluctuating unpredictably.

2. Connective tissue provides support and connects other tissues. What is the main component that gives connective tissue its strength?

• A. Collagen fibers
• B. Epithelial cells
• C. Nerve cells
• D. Blood cells

Correct answer: A

Rationale: Collagen fibers are the main component that gives connective tissue its strength. Collagen is a fibrous protein that provides structural support and tensile strength to connective tissues, allowing them to withstand stretching and tension. Epithelial cells, nerve cells, and blood cells are not the main components responsible for the strength of connective tissue. Epithelial cells are specialized for covering and lining surfaces, nerve cells transmit signals, and blood cells are involved in various functions like oxygen transport and immune response, but they do not provide the structural strength typical of collagen fibers in connective tissue.

3. The chemical equation below is unbalanced. When it is properly balanced, how many molecules of carbon dioxide (CO2) are produced for each molecule of propane (C3H8) in the reaction? 3C3H8 + 5O2 → 3CO2 + 4H2O

• A. One Half.
• B. Two.
• C. Three.
• D. Five.

Correct answer: B

Rationale: The balanced chemical equation for the combustion of propane is: 3C3H8 + 5O2 → 3CO2 + 4H2O. This equation shows that for every 3 molecules of propane (C3H8) consumed, 3 molecules of carbon dioxide (CO2) are produced. Therefore, when properly balanced, 3CO2 are produced for each molecule of propane used. Thus, the correct answer is B: Two. Choices A, C, and D are incorrect because they do not reflect the correct stoichiometry as determined by the balanced equation.

4. Which of the following joints is an example of a hinge joint?

• A. Hip joint
• B. Elbow joint
• C. Shoulder joint
• D. Knee joint

Correct answer: B

Rationale: The correct answer is B: Elbow joint. A hinge joint allows movement primarily in one plane, enabling bending and straightening actions. The elbow joint specifically functions as a hinge joint, facilitating the bending and straightening of the arm. The other options, such as the hip joint (A), shoulder joint (C), and knee joint (D), are not examples of hinge joints as they allow movement in multiple planes with more complex motions.

5. Which group of elements is known for their reactivity and ability to form strong bonds with other elements?

• A. Noble gases
• B. Halogens
• C. Alkali metals
• D. Transition metals

Correct answer: B

Rationale: Halogens are a group of elements in the periodic table known for their high reactivity and ability to form strong bonds with other elements. They possess seven valence electrons, requiring only one more electron to achieve a stable electron configuration, making them highly reactive. Halogens readily form compounds with other elements by gaining an electron to achieve a full outer shell, resulting in the formation of strong covalent bonds. Noble gases (option A), on the other hand, are known for their inertness and stable electron configurations, making them unlikely to form bonds. Alkali metals (option C) are highly reactive but do not form bonds as strong as halogens. Transition metals (option D) are recognized for their variable oxidation states and ability to create complex ions but are not as reactive as halogens when it comes to bond formation.

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