Nursing Elites

1. Carbon-12 and carbon-14 are isotopes. What do they have in common?

• A. Number of nuclear particles
• B. Number of protons
• C. Number of neutrons
• D. Mass number

Correct answer: C

Rationale: Isotopes are atoms of the same element with the same number of protons (which determines the element) but different numbers of neutrons. Both carbon-12 and carbon-14 have 6 protons (hence they are both carbon atoms) but different numbers of neutrons: carbon-12 has 6 neutrons, while carbon-14 has 8 neutrons. Therefore, the correct answer is the number of neutrons. Choices A, B, and D are incorrect because isotopes may have different numbers of nuclear particles (protons + neutrons), protons, and mass numbers, respectively.

2. Why does fluorine have a higher ionization energy than oxygen?

• A. Fluorine has a smaller number of neutrons.
• B. Fluorine has a larger number of neutrons.
• C. Fluorine has a smaller nuclear charge.
• D. Fluorine has a larger nuclear charge.

Correct answer: D

Rationale: Fluorine has a higher ionization energy than oxygen because fluorine has a larger nuclear charge. The greater number of protons in the nucleus of fluorine attracts its electrons more strongly, making it harder to remove an electron from a fluorine atom compared to an oxygen atom. Choice A is incorrect as the number of neutrons does not directly affect ionization energy. Choice B is also incorrect for the same reason. Choice C is incorrect because a smaller nuclear charge would result in lower ionization energy, not higher.

3. What is the oxidation state of the chlorine atom in the compound HCl?

• A. +1
• B. -1
• C. +2
• D. -2

Correct answer: B

Rationale: In the compound HCl (hydrochloric acid), the hydrogen atom has an oxidation state of +1 based on the rules of assigning oxidation states. Since the overall compound is neutral, the oxidation state of chlorine must be -1 to balance the charge. Chlorine typically has an oxidation state of -1 in binary compounds with nonmetals, such as HCl. Therefore, the correct answer is -1. Choices A, C, and D are incorrect as the oxidation state of chlorine in HCl is -1, not +1, +2, or -2.

4. To the nearest whole number, what is the mass of one mole of sodium chloride?

• A. 36 g/mol
• B. 43 g/mol
• C. 58 g/mol
• D. 72 g/mol

Correct answer: C

Rationale: The molar mass of sodium chloride (NaCl) is calculated by adding the atomic masses of sodium (Na) and chlorine (Cl). The atomic mass of sodium is approximately 23 g/mol and chlorine is approximately 35.5 g/mol. Adding these two atomic masses gives us a molar mass of approximately 58 g/mol for sodium chloride (NaCl). Therefore, the correct answer is C, 58 g/mol. Choice A (36 g/mol) is incorrect as it does not account for the individual atomic masses of sodium and chlorine. Choice B (43 g/mol) and choice D (72 g/mol) are also incorrect as they do not reflect the accurate molar mass of sodium chloride.

5. What effect does increasing the surface area of a reactant have?

• A. Decreases the reaction rate
• B. Has no effect
• C. Increases the reaction rate
• D. Stops the reaction

Correct answer: C

Rationale: Increasing the surface area of a reactant leads to more particles being exposed to the reaction, which in turn increases the reaction rate. This is because a larger surface area provides more sites for collisions between reacting particles, resulting in a higher frequency of successful collisions and thus accelerating the reaction. Choice A, 'Decreases the reaction rate,' is incorrect because increasing surface area actually accelerates the reaction. Choice B, 'Has no effect,' is incorrect as increasing surface area does have a significant effect on the reaction rate. Choice D, 'Stops the reaction,' is incorrect as increasing surface area does not stop the reaction but rather enhances it.

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