Nursing Elites

1. Two objects with equal masses collide head-on, both initially moving at the same speed. After the collision, they stick together. What is their final velocity?

• A. Zero
• B. Half their initial velocity
• C. Their initial velocity
• D. Twice their initial velocity

Correct answer: C

Rationale: In an inelastic collision where two objects stick together after colliding, momentum is conserved. Since the two objects have equal masses and equal initial velocities but opposite directions, their momenta cancel out. Therefore, after the collision, the combined mass will move at the same speed as the initial velocity, but in the direction of one of the objects. Choice A ('Zero') is incorrect because momentum is conserved, and the objects must move after the collision. Choice B ('Half their initial velocity') is incorrect as the final velocity is the same as the initial velocity due to momentum conservation. Choice D ('Twice their initial velocity') is incorrect as the final velocity cannot be twice the initial velocity based on the conservation of momentum principle.

2. Which of the following is a common property of bases?

• A. Conductivity in aqueous solutions
• B. Sour taste
• C. Reactivity with metals to produce hydrogen gas
• D. Turns red litmus paper blue

Correct answer: D

Rationale: Bases are substances that can accept protons or donate hydroxide ions in a chemical reaction. One common property of bases is that they turn red litmus paper blue. This is a classic test to distinguish between acids (which turn blue litmus paper red) and bases. Conductivity in aqueous solutions (Option A) is a property of both acids and bases, but not unique to bases alone. Sour taste (Option B) is a property commonly associated with acids, not bases. Reactivity with metals to produce hydrogen gas (Option C) is a property of acids, particularly strong acids, but not bases.

3. How does meiosis differ from mitosis?

• A. Meiosis is used for repairing the body. Mitosis is used for cell reproduction.
• B. Meiosis is used for sexual reproduction. Mitosis is used for asexual reproduction.
• C. Meiosis occurs in various organisms. Mitosis occurs in various organisms.
• D. Meiosis produces cells that are genetically different. Mitosis produces cells that are genetically identical.

Correct answer: D

Rationale: Meiosis is the process of cell division that results in the formation of sex cells (gametes) with only half the number of chromosomes as the parent cell, leading to genetically different cells. In contrast, mitosis is a cell division process that produces two daughter cells that are genetically identical to each other and the parent cell, maintaining the same chromosome number. Therefore, the correct answer is D, as meiosis and mitosis differ in their genetic outcomes - meiosis results in genetic diversity, while mitosis maintains genetic identity. Choices A, B, and C are incorrect because they do not accurately distinguish between meiosis and mitosis. Meiosis is not used for repairing the body or asexual reproduction, and the occurrence of both processes in various organisms does not highlight their primary differences in genetic outcomes.

4. How does the stability of an atom's nucleus influence its radioactive decay?

• A. Stable nuclei never undergo radioactive decay.
• B. Unstable nuclei are more likely to decay through various processes.
• C. Decay releases energy, making stable nuclei more prone to it.
• D. The element's position on the periodic table determines its decay rate.

Correct answer: B

Rationale: Unstable nuclei are more likely to decay through various processes. The stability of an atom's nucleus is a crucial factor in determining whether it will undergo radioactive decay. Unstable nuclei have an excess of either protons or neutrons, causing an imbalance in the nucleus. To achieve a more stable configuration, these nuclei will undergo radioactive decay by emitting particles or energy. On the contrary, stable nuclei are less likely to undergo radioactive decay as they possess a balanced number of protons and neutrons. Choice A is incorrect because stable nuclei can still undergo radioactive decay, albeit less frequently. Choice C is incorrect as decay does not make stable nuclei more prone to it; rather, it stabilizes them. Choice D is incorrect because an element's decay rate is primarily determined by the nucleus's stability, not its position on the periodic table.

5. What type of bond is formed when electrons are transferred between atoms?

• A. Transfer bond
• B. Static bond
• C. Covalent bond
• D. Ionic bond

Correct answer: D

Rationale: The correct answer is 'D: Ionic bond.' An ionic bond is formed when electrons are transferred between atoms. In an ionic bond, one atom donates electrons to another atom, resulting in the formation of positively and negatively charged ions that are attracted to each other, creating a strong bond. Choice A, 'Transfer bond,' is incorrect because there is no common term known as a 'Transfer bond' in chemistry. Choice B, 'Static bond,' is incorrect as it does not describe the process of electron transfer between atoms. Choice C, 'Covalent bond,' is incorrect because in a covalent bond, electrons are shared between atoms rather than transferred outright, making it different from an ionic bond.

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