Nursing Elites

1. What is the mass number of an atom with 6 protons, 6 neutrons, and 6 electrons?

• A. 12
• B. 18
• C. 6
• D. 8

Correct answer: A

Rationale: The mass number of an atom is the sum of protons and neutrons. In this case, the atom has 6 protons and 6 neutrons, thus the mass number is 6 + 6 = 12. Therefore, choice A (12) is the correct answer. Choices B (18), C (6), and D (8) are incorrect because the mass number is determined by the sum of protons and neutrons, not the number of electrons or a different combination of particles.

2. You contain two odorous gases in vials with porous plugs. Gas A has twice the mass of Gas B. Which observation is most likely?

• A. You will smell Gas A before you smell Gas B.
• B. You will smell Gas B before you smell Gas A.
• C. You will smell Gas A but not Gas B.
• D. You will smell Gas B but not Gas A.

Correct answer: A

Rationale: The rate of effusion of a gas is inversely proportional to the square root of its molar mass. Since Gas A has twice the mass of Gas B, Gas A will effuse more slowly than Gas B. Therefore, you will likely smell Gas A before you smell Gas B as Gas A will escape and diffuse through the porous plug at a slower rate compared to Gas B. Choice A is correct because Gas A, with its higher molar mass, will take longer to effuse through the porous plug, causing you to smell it first. Choices B, C, and D are incorrect as they do not consider the relationship between molar mass and effusion rate.

3. To the nearest whole number, what is the mass of one mole of hydrogen iodide?

• A. 2 g/mol
• B. 58 g/mol
• C. 87 g/mol
• D. 128 g/mol

Correct answer: C

Rationale: The molar mass of hydrogen iodide (HI) is the sum of the atomic masses of its constituent elements. Hydrogen (H) has a molar mass of approximately 1 g/mol, and iodine (I) has a molar mass of about 127 g/mol. Thus, the molar mass of hydrogen iodide (HI) is approximately 1 + 127 = 128 g/mol. Rounding to the nearest whole number, the molar mass of hydrogen iodide is 128 g/mol, which is closest to choice C. Choice A (2 g/mol) is too low and does not reflect the correct molar mass of hydrogen iodide. Choice B (58 g/mol) is significantly lower than the actual molar mass. Choice D (128 g/mol) matches the calculated molar mass but is not the nearest whole number as requested.

4. What is the oxidation state of the sulfur atom in sulfuric acid H2SO4?

• A. 4
• B. 6
• C. 8
• D. 10

Correct answer: B

Rationale: In sulfuric acid (H2SO4), sulfur has an oxidation state of +6. The oxidation state is determined by considering the overall charge of the compound and the known oxidation states of other elements. In this case, hydrogen is typically +1, and oxygen is -2. To balance the charges and match the compound's overall charge of 0, sulfur must have an oxidation state of +6. Choice A (4) is incorrect because it doesn't balance the charges in the compound. Choices C (8) and D (10) are also incorrect as they are not valid oxidation states for sulfur in this compound.

5. What charge do Group VIA elements typically have?

• A. -1
• B. -2
• C. -3
• D. 0

Correct answer: B

Rationale: Group VIA elements, also known as Group 16 elements, typically have a charge of -2. This is because they have 6 valence electrons and tend to gain 2 electrons to achieve a stable octet configuration, resulting in a -2 charge. Choice A (-1) is incorrect as Group VIA elements need to gain 2 electrons for stability, not just 1. Choice C (-3) is incorrect because Group VIA elements do not need to gain 3 electrons to achieve stability. Choice D (0) is incorrect as Group VIA elements need to gain electrons to reach a stable configuration, resulting in a negative charge.

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