Nursing Elites

1. What type of bond forms between elements when they share electrons?

• A. Covalent bond
• B. Ionic bond
• C. Metallic bond
• D. Hydrogen bond

Correct answer: A

Rationale: In a covalent bond, atoms share electrons, creating a strong attraction that holds them together

2. Half-life refers to the characteristic time it takes for:

• A. Radioactive intensity to completely disappear
• B. The number of neutrons in a nucleus to double
• C. The number of protons in a nucleus to change
• D. An isotope to decay by half of its initial quantity

Correct answer: D

Rationale: The correct answer is D: An isotope to decay by half of its initial quantity. The half-life of a substance is the time it takes for half of the initial quantity of radioactive atoms to decay. This is a characteristic property of each radioactive isotope and is used to determine the rate of decay of a substance. Option A is incorrect because radioactive intensity does not completely disappear in half-life, it only decreases by half. Options B and C are unrelated to the concept of half-life and do not accurately describe its definition.

3. Which of the following describes a scalar quantity?

• A. Velocity
• B. Acceleration
• C. Force
• D. Speed

Correct answer: d

Rationale: Speed is a scalar quantity as it only indicates how fast an object is moving without any directional information.

4. The outermost layer of the skin, providing protection against pathogens and the environment, is the:

• A. Dermis
• B. Epidermis
• C. Hypodermis
• D. Stratum corneum (part of the epidermis)

Correct answer: D

Rationale: The correct answer is D, 'Stratum corneum (part of the epidermis).' The stratum corneum is the outermost layer of the epidermis, consisting of dead skin cells that provide a protective barrier against pathogens and environmental factors. The dermis is located beneath the epidermis and contains connective tissue, nerves, and blood vessels. The hypodermis is the deepest layer of the skin, consisting of fat and connective tissue. Understanding the layers of the skin and their functions is essential for comprehending the skin's role in protecting the body.

5. Which of the following is an example of a chemical change?

• A. Dissolving sugar in water
• B. Boiling water
• C. Rusting iron
• D. Crushing ice

Correct answer: C

Rationale: Rusting is a chemical reaction where iron reacts with oxygen and water to form iron oxide (rust).

6. The speed of light in a vacuum is measured in units of:

• A. Meters per second
• B. Hertz
• C. Candela
• D. Newton

Correct answer: A

Rationale: The correct answer is A: 'Meters per second.' The speed of light in a vacuum is a fundamental constant of nature and is approximately 299,792,458 meters per second. This speed is constant and does not vary based on the frequency or wavelength of light. Hertz (B) is a unit of frequency, Candela (C) is a unit of luminous intensity, and Newton (D) is a unit of force. Understanding the units used to measure the speed of light is important in physics and related fields to accurately describe the propagation of light in different mediums.

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