Nursing Elites

1. Which of the following is an example of a salt?

• A. Sodium hydroxide (NaOH)
• B. Hydrochloric acid (HCl)
• C. Sodium chloride (NaCl)
• D. Sulfuric acid (Hâ‚‚SOâ‚„)

Correct answer: c

Rationale: Sodium chloride is an example of a salt. The other choices are either bases or acids.

2. What is the periodic table?

• A. A table of elements that are arranged in order of increasing atomic number.
• B. A table of elements that are arranged in order of increasing atomic mass.
• C. A table of elements that are arranged in order of their reactivity.
• D. A table of elements that are arranged in order of their color.

Correct answer: B

Rationale: The periodic table is a tabular arrangement of the chemical elements, organized on the basis of their atomic number, electron configurations, and recurring chemical properties. Elements are arranged in rows (periods) and columns (groups) with similar properties. The elements are listed in order of increasing atomic number, which is the number of protons in the nucleus of an atom. This arrangement reveals a periodic repetition of chemical properties, which is the basis of the periodic law.

3. What is the building block of RNA?

• A. Amino acid
• B. Nucleotide
• C. Protein
• D. Fatty acid

Correct answer: B

Rationale: Rationale: A) Amino acid: Amino acids are the building blocks of proteins, not RNA. B) Nucleotide: Nucleotides are the building blocks of RNA. A nucleotide consists of a nitrogenous base (adenine, guanine, cytosine, or uracil in RNA), a sugar (ribose in RNA), and a phosphate group. C) Protein: Proteins are made up of amino acids, not nucleotides. D) Fatty acid: Fatty acids are components of lipids, not RNA.

4. 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.

5. 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.

6. What is the coefficient of oxygen in the balanced chemical equation for the combustion of methane (CH4)?

• A. 1
• B. 2
• C. 3
• D. 4

Correct answer: b

Rationale: The balanced equation is CH4 + 2O2 → CO2 + 2H2O, so the coefficient of oxygen is 2.

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