Nursing Elites

1. How many electrons are typically found in each shell of a neutral aluminum atom with 13 electrons in its electron cloud?

• A. 6 in the first shell, 7 in the second shell
• B. 2 in the first shell, 11 in the second shell
• C. 2 in the first shell, 8 in the second shell, 3 in the third shell
• D. 3 in the first shell, 5 in the second shell, 5 in the third shell

Correct answer: C

Rationale: In a neutral aluminum atom with 13 electrons, the electron distribution typically follows the electron shell filling order based on the Aufbau principle. The first shell can hold a maximum of 2 electrons, the second shell can hold up to 8 electrons, and the third shell can hold up to 8 electrons as well. Therefore, the distribution would be 2 electrons in the first shell, 8 electrons in the second shell, and 3 electrons in the third shell, totaling 13 electrons. Choice A is incorrect as it exceeds the maximum number of electrons the shells can hold. Choice B is incorrect as it does not distribute the electrons correctly among the shells. Choice D is incorrect as it also does not distribute the electrons correctly among the shells.

2. Which sentence avoids a comma splice?

• A. The wind howled, the branches swayed, and rain lashed against the windows.
• B. He packed his bags, checked the weather forecast, and then hit the road.
• C. The movie was entertaining; it was also thought-provoking.
• D. Tired and hungry, she stopped for a quick bite at the cafe.

Correct answer: C

Rationale: Option C uses a semicolon to correctly separate the two independent clauses 'The movie was entertaining' and 'it was also thought-provoking.' This usage of a semicolon avoids a comma splice, which occurs when two independent clauses are incorrectly joined by a comma without a coordinating conjunction or appropriate punctuation. Choices A, B, and D are incorrect because they all contain comma splices. In choice A, the comma splice is present between 'The wind howled' and 'the branches swayed.' In choice B, the comma splice occurs between 'He packed his bags' and 'checked the weather forecast.' Choice D has a comma splice between 'Tired and hungry' and 'she stopped for a quick bite at the cafe.'

3. What is the formula for calculating molarity?

• A. M = n/V
• B. M = n/L
• C. M = mol/L
• D. M = mol/dm³

Correct answer: A

Rationale: The correct formula for calculating molarity is M = n/V. In this formula, 'M' represents molarity, 'n' represents the number of moles of solute, and 'V' represents the volume of the solution in liters. Molarity is defined as the number of moles of solute per liter of solution, hence the ratio of moles to volume. Choice B, 'M = n/L', is incorrect because 'L' should represent liters instead of the number of moles. Choice C, 'M = mol/L', is incorrect as it does not include the representation of the number of moles 'n'. Choice D, 'M = mol/dm³', is incorrect because 'dm³' is a volume unit equal to a liter, but the correct representation should be in terms of the volume of the solution in liters. Therefore, the correct answer is M = n/V.

4. What is the oxidation state of carbon in CH4?

• A. +1
• B. -1
• C. +2
• D. -4

Correct answer: D

Rationale: In CH4 (methane), carbon is bonded to four hydrogen atoms. Hydrogen has an oxidation state of +1. Since the overall charge of CH4 is 0, the oxidation state of carbon must be -4 to balance the charges. Each hydrogen contributes an oxidation state of +1, resulting in a total of +4 from hydrogen atoms. To achieve a total oxidation state of 0 for the molecule, carbon must have an oxidation state of -4 to offset the contribution from hydrogen. Therefore, the correct answer is -4. Choices A, B, and C are incorrect: +1 is the oxidation state of hydrogen, -1 is not the oxidation state of carbon in methane, and +2 is not the correct oxidation state of carbon in CH4.

5. Which of the following sentences correctly uses a semicolon?

• A. I have a big test tomorrow; I can't go out tonight.
• B. I have a big test tomorrow; I can't go out tonight.
• C. I have a big test tomorrow; and I can't go out tonight.
• D. I have a big test tomorrow; but I can't go out tonight.

Correct answer: A

Rationale: The correct use of a semicolon is to join two closely related independent clauses. Choice A is the only option that correctly uses a semicolon to connect two independent clauses: 'I have a big test tomorrow' and 'I can't go out tonight.' Choice B incorrectly uses a comma instead of a semicolon. Choice C adds an unnecessary 'and' after the semicolon, which disrupts the correct punctuation usage. Choice D introduces a contradictory conjunction 'but' after the semicolon, which is not necessary for the given context. Therefore, the correct answer is A.

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