Nursing Elites

1. The molar mass of some gases is as follows: carbon monoxide—28.01 g/mol; helium—4.00 g/mol; nitrogen—28.01 g/mol; and oxygen—32.00 g/mol. Which would you expect to diffuse most rapidly?

• A. Carbon monoxide
• B. Helium
• C. Nitrogen
• D. Oxygen

Correct answer: B

Rationale: The rate of diffusion is inversely proportional to the molar mass of the gas. Helium has the lowest molar mass among the given gases, making it the lightest and fastest gas to diffuse. Therefore, helium would be expected to diffuse most rapidly compared to carbon monoxide, nitrogen, and oxygen. Carbon monoxide, nitrogen, and oxygen have higher molar masses than helium, so they would diffuse more slowly. Therefore, the correct answer is helium.

2. How many protons does Potassium have?

• A. 18
• B. 19
• C. 20
• D. 21

Correct answer: B

Rationale: Potassium, with the atomic symbol K, has 19 protons, which is equal to its atomic number. The number of protons determines the element's identity, and in the case of Potassium, it is 19. Choice A (18) is incorrect as it does not correspond to Potassium's proton number. Choice C (20) and Choice D (21) are also incorrect as they do not match the actual number of protons in Potassium.

3. What is 119 K in degrees Celsius?

• A. 32°C
• B. -154°C
• C. 154°C
• D. 0°C

Correct answer: B

Rationale: To convert Kelvin (K) to Celsius (°C), you subtract 273.15 from the Kelvin value. Therefore, 119 K - 273.15 = -154.15°C. The negative sign indicates that the temperature is below freezing. When rounded to the nearest whole number, -154.15°C is approximately -154°C. Choice A and Choice C are incorrect as they do not reflect the correct conversion from Kelvin to Celsius. Choice D is incorrect as it corresponds to the freezing point of water in Celsius, not the conversion of 119 K.

4. If electrons are not shared equally in a covalent bond, the bond is what?

• A. Polar
• B. Non-polar
• C. Ionic
• D. Hydrogen

Correct answer: A

Rationale: A polar covalent bond occurs when electrons are shared unequally between atoms. In this type of bond, one atom has a stronger pull on the shared electrons, leading to a partial positive and partial negative charge distribution within the molecule. Choice B, non-polar, is incorrect because in non-polar covalent bonds, electrons are shared equally between atoms. Choice C, ionic, is incorrect as ionic bonds involve a transfer of electrons rather than sharing. Choice D, hydrogen, is incorrect as it does not describe the nature of a covalent bond.

5. 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.

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