Nursing Elites

1. The number of protons in the nucleus of an atom determines its:

• A. Mass number
• B. Atomic number
• C. Isotope
• D. Valence electron count

Correct answer: B

Rationale: The atomic number (Z) equals the number of protons in the nucleus and uniquely identifies an element. Mass number (A) includes both protons and neutrons, isotopes have different neutron numbers, and valence electrons are involved in bonding, not atomic identity.

2. Explain how a single gene mutation can lead to multiple phenotypes depending on the organism.

• A. Pleiotropy describes the effect of one gene influencing multiple seemingly unrelated traits.
• B. Epigenetics involves environmental factors modifying gene expression without altering the DNA sequence.
• C. Genetic drift refers to random changes in allele frequencies within a population.
• D. Gene regulation controls the timing and level of gene expression within an organism.

Correct answer: A

Rationale: A single gene mutation can affect different biochemical pathways or developmental processes, leading to a cascade of downstream effects and diverse phenotypic consequences.

3. What is the primary factor that determines whether a solute will dissolve in a solvent?

• A. Temperature
• B. Pressure
• C. Molecular structure
• D. Particle size

Correct answer: c

Rationale: The molecular structure of the solute and solvent plays a key role in determining solubility. The other choices may influence solubility but are not the primary determining factor.

4. The process of mixing two or more substances to form a heterogeneous mixture is called:

• A. Dissolving
• B. Diluting
• C. Mixing
• D. Reacting

Correct answer: C

Rationale: Mixing results in a heterogeneous mixture where the components are physically distinguishable, unlike solutions where everything dissolves uniformly

5. 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.

6. Which type of waves exhibit both longitudinal and transverse motion?

• A. Electromagnetic waves
• B. Surface waves
• C. Mechanical waves
• D. Sound waves

Correct answer: b

Rationale: Surface waves, like those on water surfaces, exhibit both longitudinal and transverse motion.

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