Nursing Elites

1. Which type of reaction is represented by the equation A + B → AB?

• A. Synthesis
• B. Decomposition
• C. Single Replacement
• D. Double Replacement

Correct answer: a

Rationale: Synthesis reactions involve the combination of two or more substances to form a new compound.

2. Which of the following is responsible for generating the electrical impulses that regulate the heartbeat?

• A. Aorta
• B. Pulmonary veins
• C. Coronary arteries
• D. Sinoatrial (SA) node

Correct answer: D

Rationale: The correct answer is D: Sinoatrial (SA) node. The SA node, also known as the heart's natural pacemaker, is responsible for generating the electrical impulses that regulate the heartbeat. These impulses initiate each heartbeat by causing the atria to contract. The other options, Aorta, Pulmonary veins, and Coronary arteries, are important structures in the cardiovascular system but are not directly responsible for generating the electrical impulses that regulate the heartbeat.

3. The Becquerel (Bq) is the designated unit for quantifying:

• A. Electron volt (eV) measurements of energy
• B. Radioactivity
• C. Electric charge (Coulombs)
• D. Force (Newtons)

Correct answer: B

Rationale: The Becquerel (Bq) is the designated unit for quantifying radioactivity. Radioactivity is the measure of the rate at which radioactive atoms undergo nuclear decay and emit radiation. One Becquerel is equal to one nuclear decay event per second. This unit is named after Henri Becquerel, the scientist who discovered radioactivity. Therefore, option B, 'Radioactivity,' is the correct answer. Electron volt (eV) measurements of energy are quantified using a different unit, electric charge is measured in Coulombs, and force is quantified in Newtons, making them incorrect choices for this question.

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. he adrenal cortex produces a group of steroid hormones called corticosteroids. What is a MAJOR function of corticosteroids?

• A. Regulate insulin sensitivity and blood sugar levels
• B. Control blood pressure and electrolyte balance
• C. Stimulate the immune system and inflammatory response
• D. Promote growth and development during puberty

Correct answer: B

Rationale: The correct answer is B: 'Control blood pressure and electrolyte balance.' Corticosteroids, produced by the adrenal cortex, play a major role in regulating blood pressure and electrolyte balance in the body. These hormones, such as aldosterone, act on the kidneys to control the reabsorption of sodium and water, which in turn affects blood pressure and electrolyte levels. While corticosteroids can have effects on other physiological processes, their primary function is to regulate blood pressure and electrolyte balance, making option B the most appropriate choice in this context.

6. 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: Moving down a group, additional electron shells increase the distance from the nucleus, leading to larger atomic radii. Moving across a period, the number of electron shells remains constant, but the increasing nuclear charge pulls electrons closer, resulting in smaller radii.

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