Nursing Elites

1. What happens to the acceleration of an object when the force acting on it is increased, assuming the mass remains constant?

• A. Acceleration increases
• B. Acceleration decreases
• C. Acceleration remains constant
• D. Acceleration becomes zero

Correct answer: a

Rationale: According to Newton's second law (F = ma), if mass is constant and force increases, acceleration also increases.

2. In an SN2 reaction, the rate of the reaction is affected by

• A. Only the concentration of the nucleophile
• B. Only the concentration of the electrophile
• C. Neither the concentration of the nucleophile nor the electrophile
• D. Both the concentration of the nucleophile and the electrophile

Correct answer: D

Rationale: In an SN2 reaction, the rate of the reaction is affected by both the concentration of the nucleophile and the electrophile. This is because in an SN2 reaction, the nucleophile directly attacks the electrophilic center, leading to the formation of the product. A higher concentration of nucleophile increases the chances of successful collisions with the electrophile, thereby increasing the reaction rate. Similarly, a higher concentration of the electrophile provides more reaction sites for the nucleophile to attack, also increasing the rate of the reaction. Therefore, both the nucleophile and electrophile concentrations play crucial roles in determining the rate of an SN2 reaction.

3. What type of reaction is represented by the following equation: Fe2O3 (s) + 3H2 (g) -> 2Fe (s) + 3H2O (g)

• A. Combustion
• B. Decomposition
• C. Single displacement
• D. Redox reaction

Correct answer: D

Rationale: The given equation involves a transfer of electrons from iron oxide (Fe2O3) to hydrogen gas (H2), resulting in the formation of iron (Fe) and water (H2O). This transfer of electrons indicates a redox reaction, where oxidation and reduction occur simultaneously. In this case, iron is reduced from a higher oxidation state in Fe2O3 to a lower oxidation state in Fe, while hydrogen is oxidized from its elemental state in H2 to form water. Therefore, the correct answer is D: Redox reaction.

4. The involuntary, rhythmic contractions of the heart muscle are controlled by a specialized group of cells located in the:

• A. Lungs
• B. Brain
• C. Spinal cord
• D. Sinoatrial node (located within the heart)

Correct answer: D

Rationale: The correct answer is D: Sinoatrial node (located within the heart). The sinoatrial node, also known as the heart's natural pacemaker, is a cluster of specialized cells within the heart that controls the heart rate by initiating the electrical impulses that regulate the heart's contractions. The lungs (A), brain (B), and spinal cord (C) do not directly control the rhythmic contractions of the heart muscle. Therefore, the sinoatrial node is the specific anatomical location responsible for regulating the heart's rhythmic contractions, making it the correct answer.

5. Fertilization, the fusion of sperm and egg, typically occurs in which part of the female reproductive system?

• A. Ovary
• B. Fallopian tube
• C. Uterus
• D. Vagina

Correct answer: B

Rationale: The correct answer is B: Fallopian tube. Fertilization usually occurs in the fallopian tube. After ovulation, the egg is released from the ovary into the fallopian tube where it can be fertilized by sperm. The fallopian tube provides the ideal environment for fertilization to take place before the fertilized egg travels to the uterus for implantation. The other options, such as the ovary, uterus, and vagina, do not typically serve as the site of fertilization. Therefore, the fallopian tube is the correct answer in this case.

6. What is the Aufbau principle?

• A. The principle that electrons fill orbitals in order of increasing energy.
• B. The principle that electrons cannot be in the same orbital with the same spin.
• C. The principle that the maximum number of electrons in an orbital is 2n^2, where n is the energy level of the orbital.
• D. The principle that the attractive force between an electron and the nucleus is inversely proportional to the distance between them.

Correct answer: A

Rationale: The Aufbau principle is a fundamental concept in atomic structure that determines the order in which electrons fill the available orbitals in an atom. It states that electrons occupy orbitals in order of increasing energy levels, starting with the lowest energy level and progressing to higher energy levels. This principle is based on the fact that electrons in lower energy levels are more stable and have a lower energy state than electrons in higher energy levels.

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