Nursing Elites

1. Which element has the chemical symbol 'Fe'?

• A. Lead
• B. Iron
• C. Silver
• D. Copper

Correct answer: B

Rationale: The correct answer is 'Iron' as it has the chemical symbol 'Fe'. Chemical symbols are used to represent elements in the periodic table, and 'Fe' specifically refers to Iron. Choice A, Lead, is incorrect as the chemical symbol for Lead is 'Pb'. Choice C, Silver, is incorrect as the chemical symbol for Silver is 'Ag'. Choice D, Copper, is incorrect as the chemical symbol for Copper is 'Cu'. Therefore, 'Iron' is the only element among the choices with the chemical symbol 'Fe'.

2. If gas A has four times the molar mass of gas B, you would expect it to diffuse through a plug ___________.

• A. at half the rate of gas B
• B. at twice the rate of gas B
• C. at a quarter the rate of gas B
• D. at four times the rate of gas B

Correct answer: A

Rationale: When comparing the diffusion rates of two gases, according to Graham's law of diffusion, the rate of diffusion is inversely proportional to the square root of the molar mass. If gas A has four times the molar mass of gas B, the square root of the molar masses ratio (4:1) is 2. This means that gas A would diffuse through a plug at half the rate of gas B. Therefore, the correct answer is A, at half the rate of gas B. Choices B, C, and D are incorrect because they do not reflect the correct relationship between the molar masses and the rates of diffusion according to Graham's law.

3. Which type of chemical reaction involves two ionic compounds where the reactants yield 'switched partners'?

• A. Single replacement
• B. Double replacement
• C. Synthesis
• D. Decomposition

Correct answer: B

Rationale: The correct answer is 'Double replacement.' In a double replacement reaction, two ionic compounds react by exchanging ions, resulting in the formation of two new compounds where the positive and negative ions have 'switched partners.' This type of reaction is characterized by the exchange of ions between the reactants. Choice A, 'Single replacement,' involves an element replacing another in a compound, not the exchange of partners like in the given scenario. Choice C, 'Synthesis,' is the combination of two or more substances to form a more complex product, not involving the exchange of partners. Choice D, 'Decomposition,' is the breakdown of a compound into simpler substances, which is different from the scenario described in the question.

4. At what temperature does water boil in °F?

• A. 210°F
• B. 212°F
• C. 215°F
• D. 220°F

Correct answer: B

Rationale: Water boils at 212°F under standard atmospheric pressure. This is the point at which water changes from a liquid to a gas phase. Choice A (210°F) is incorrect as it is below the boiling point of water. Choice C (215°F) and Choice D (220°F) are also incorrect as they are above the boiling point of water.

5. Cobalt-60 has a half-life of 5 years. If you start with 20 g of cobalt-60, how much is left after 10 years?

• A. 15 g
• B. 10 g
• C. 5 g
• D. 2.5 g

Correct answer: C

Rationale: Cobalt-60's half-life of 5 years means that after 5 years, half of the initial amount remains. Therefore, after 10 years, a quarter (half of a half) of the initial amount will remain. Starting with 20 g, after 10 years, 5 g of cobalt-60 will be left. Choice A (15 g) is incorrect because it assumes a linear decrease, not considering the exponential decay characteristic of radioactive substances. Choice B (10 g) is incorrect as it overlooks that after 10 years, more decay has occurred. Choice D (2.5 g) is incorrect as it represents only an eighth of the initial amount after 10 years, not a quarter.

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