Nursing Elites

1. How many neutrons does carbon-14 have?

• A. 10
• B. 8
• C. 6
• D. 12

Correct answer: B

Rationale: The correct answer is B: 8. Carbon-14 is an isotope of carbon with 6 protons and 8 neutrons. To determine the number of neutrons in an atom, subtract the atomic number (number of protons) from the mass number. In this case, the mass number of carbon-14 is 14, and the atomic number of carbon is 6. Therefore, 14 (mass number) - 6 (atomic number) = 8 neutrons. Choices A, C, and D are incorrect because they do not reflect the correct number of neutrons in a carbon-14 atom.

2. Which of the following substances is a base?

• A. Water
• B. Sodium chloride
• C. Ammonia
• D. Salt

Correct answer: C

Rationale: The correct answer is 'Ammonia' (Choice C) as it is a common example of a base. Bases are substances that release hydroxide ions (OH-) in aqueous solutions, helping to increase the pH level. Ammonia is a weak base that can accept a proton (H+) to form ammonium hydroxide. In contrast, water (Choice A), sodium chloride (Choice B), and salt (Choice D) are not bases; water is neutral, while sodium chloride and salt are neutral compounds composed of a cation and an anion.

3. How are elements arranged in the periodic table?

• A. By their atomic mass
• B. By their chemical properties
• C. By their physical state
• D. By their charge

Correct answer: B

Rationale: Elements are arranged in the periodic table based on their chemical properties, making choice B the correct answer. The periodic table is organized so that elements with similar chemical properties are grouped together in columns, known as groups or families. This arrangement allows for the identification of trends in the behavior of elements and predicting their properties based on their position in the table. Choices A, C, and D are incorrect because the periodic table primarily focuses on the chemical properties of elements, not solely on atomic mass, physical state, or charge.

4. Which of these types of intermolecular force is weakest?

• A. Dipole-dipole interaction
• B. London dispersion force
• C. Hydrogen bonding
• D. Ionic bonding

Correct answer: B

Rationale: The correct answer is B, London dispersion force. London dispersion forces are the weakest type of intermolecular force among the options provided. These forces arise from temporary fluctuations in electron distribution within molecules, leading to temporary dipoles. London dispersion forces are present in all molecules and are generally weaker than dipole-dipole interactions, hydrogen bonding, and ionic bonding. Dipole-dipole interactions are stronger than London dispersion forces as they involve permanent dipoles in molecules. Hydrogen bonding is stronger than both London dispersion and dipole-dipole interactions as it is a special type of dipole-dipole interaction that occurs when hydrogen is bonded to highly electronegative atoms like oxygen or nitrogen. Ionic bonding is the strongest type of intermolecular force among the options, but it is not the correct answer for the weakest type of force.

5. What is the correct name of ZnSOâ‚„?

• A. Zinc sulfate
• B. Zinc sulfide
• C. Zinc sulfur
• D. Zinc oxide

Correct answer: A

Rationale: The correct name of ZnSO₄ is zinc sulfate. In this compound, zinc is combined with the polyatomic ion sulfate (SO₄). Sulfate is a common anion formed from sulfur and oxygen atoms. Therefore, the correct name for ZnSO₄ is zinc sulfate. Choice B, Zinc sulfide, is incorrect because sulfide is a different anion (S²⁻) compared to sulfate (SO₄²⁻). Choice C, Zinc sulfur, is incorrect as it does not represent the correct anion in the compound. Choice D, Zinc oxide, is incorrect as it involves an oxygen anion, not sulfate.

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