Nursing Elites

1. What is the mass number of an element?

• A. The number of protons in an atom's nucleus.
• B. The number of neutrons in an atom's nucleus.
• C. The number of electrons in an atom's valence shell.
• D. The number of isotopes of an element.

Correct answer: B

Rationale: The mass number of an element is the total number of protons and neutrons in the nucleus of an atom. It is represented by the symbol A and is written as a superscript to the element's symbol. For example, the mass number of carbon-12 is 12, which means that a carbon-12 atom has 6 protons and 6 neutrons in its nucleus.

2. What is the atomic number of an element?

• A. The number of protons in an atom's nucleus.
• B. The number of neutrons in an atom's nucleus.
• C. The number of electrons in an atom's valence shell.
• D. The number of isotopes of an element.

Correct answer: B

Rationale: The atomic number of an element is a fundamental property that defines the identity of an element. It is the number of protons in the nucleus of an atom. The number of protons determines the element's position in the periodic table and its chemical properties.

3. What term describes the bending of waves around obstacles or through openings?

• A. Reflection
• B. Refraction
• C. Diffraction
• D. Absorption

Correct answer: c

Rationale: Diffraction occurs when waves bend around obstacles or spread after passing through small openings.

4. What is the feedback mechanism in the endocrine system that helps maintain hormone balance?

• A. Positive feedback, where a hormone stimulates its own release
• B. Negative feedback, where a hormone suppresses its own release
• C. Cascade effect, where one hormone triggers the release of another
• D. Dual hormone system, where two hormones work together

Correct answer: B

Rationale: The correct answer is B: Negative feedback, where a hormone suppresses its own release. In the endocrine system, negative feedback is a crucial mechanism that helps maintain hormone balance. When hormone levels rise, they signal the body to decrease further hormone production, preventing an excess. This ensures that hormone levels stay within a narrow range, promoting stability and homeostasis. Positive feedback (option A) would lead to an amplification of hormone release, which is not ideal for maintaining balance. Cascade effect (option C) involves a sequential activation of hormones but does not directly regulate hormone levels. Dual hormone system (option D) refers to two hormones working together but doesn't specifically address the feedback mechanism for maintaining hormone balance.

5. Which word best completes the sentence: "The scientist conducted the experiment with _____ precision."

• A. extreme
• B. great
• C. utter
• D. remarkable

Correct answer: C

Rationale: Option C emphasizes the absolute and complete accuracy of the experiment.

6. Which hormone, produced by the pancreas, is released in response to low blood sugar levels and stimulates the release of glucose into the bloodstream?

• A. Insulin
• B. Glucagon
• C. Cortisol
• D. Thyroxine

Correct answer: b

Rationale: The correct answer is B: Glucagon. Glucagon is a hormone produced by the pancreas that is released in response to low blood sugar levels, also known as hypoglycemia. When blood sugar levels drop, glucagon acts to stimulate the liver to release stored glucose into the bloodstream, helping to raise blood sugar levels back to a normal range. Insulin, on the other hand, is released in response to high blood sugar levels and helps to lower blood sugar by promoting the uptake of glucose by cells. Cortisol is a stress hormone produced by the adrenal glands, and thyroxine is a hormone produced by the thyroid gland that regulates metabolism. Therefore, glucagon is the hormone specifically responsible for stimulating the release of glucose into the bloodstream in response to low blood sugar levels.

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