Nursing Elites

1. What is the main component of air?

• A. Oxygen
• B. Nitrogen
• C. Carbon dioxide
• D. Argon

Correct answer: B

Rationale: Nitrogen is the main component of air, constituting approximately 78% of the Earth's atmosphere. Oxygen, carbon dioxide, and argon are also present in smaller amounts, but nitrogen is the most abundant gas in the air. Therefore, the correct answer is B. Choice A, oxygen, is essential for respiration but makes up only about 21% of the atmosphere. Choice C, carbon dioxide, is vital for photosynthesis but exists in trace amounts in the air. Choice D, argon, is a noble gas found in relatively small quantities in the atmosphere.

2. Why are bacteria and blue-green algae often classified together?

• A. Both are gymnosperms.
• B. Both are prokaryotes.
• C. Both are autotrophs.
• D. Both are pathogens.

Correct answer: B

Rationale: Bacteria and blue-green algae (cyanobacteria) are often classified together because they are both prokaryotes. Prokaryotes are unicellular organisms that lack a membrane-bound nucleus and other membrane-bound organelles. This characteristic distinguishes them from eukaryotic organisms, which have these membrane-bound structures. Choice A is incorrect because gymnosperms are seed-producing plants with naked seeds, not bacteria or blue-green algae. Choice C is incorrect because being an autotroph (able to produce its own food) is not a reason for classifying them together. Choice D is incorrect because not all bacteria and blue-green algae are pathogens; many of them are beneficial or neutral to other organisms.

3. How many liters are in 300 milliliters?

• A. 0.3 liters
• B. 3 liters
• C. 0.03 liters
• D. 3.3 liters

Correct answer: A

Rationale: 300 milliliters is equivalent to 0.3 liters. To convert milliliters to liters, you need to move the decimal three places to the left. Therefore, the correct answer is A. Choice B (3 liters) is incorrect as it represents the conversion of 3000 milliliters. Choice C (0.03 liters) is incorrect as it represents the conversion of 30 milliliters. Choice D (3.3 liters) is also incorrect as it is not the correct conversion of 300 milliliters.

4. Percent (%) is a way to express a fraction with a denominator of 100. 125% can be expressed as a fraction in lowest terms. Which of the following represents 125% as a fraction?

• A. 5/4
• B. 1/8
• C. 5/2
• D. 25/2

Correct answer: A

Rationale: Percent (%) represents a value out of 100. To convert 125% to a fraction, it is 125/100. Simplifying 125/100 by dividing both the numerator and denominator by 25 gives us 5/4. Therefore, the correct answer is A. Choice B (1/8), Choice C (5/2), and Choice D (25/2) do not represent 125% as a fraction in lowest terms.

5. Which substance forms hydroxide ions when placed in water?

• A. Lemon juice
• B. Battery acid
• C. Vinegar
• D. Lye

Correct answer: D

Rationale: The correct answer is D, lye. Lye, also known as sodium hydroxide (NaOH), is a strong base that forms hydroxide ions (OH-) when placed in water. When lye dissolves in water, it dissociates into sodium ions (Na+) and hydroxide ions, making it an alkaline substance. Lemon juice, battery acid, and vinegar do not form hydroxide ions when placed in water. Lemon juice contains citric acid, battery acid contains sulfuric acid, and vinegar contains acetic acid, none of which produce hydroxide ions when dissolved in water.

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