HESI A2 Chemistry

Correct Answer: C

Rationale: The correct answer is C: Between 6 and 8. Tap water is typically slightly alkaline, with a pH range between 6.5 and 8.5. This is considered neutral to slightly basic, as pure water has a pH of 7. The pH scale ranges from 0 to 14, with 7 being neutral. Choices A, B, and D are incorrect because tap water is not highly acidic (A), acidic (B), or highly alkaline (D). Tap water falls within the slightly basic range on the pH scale.

Correct Answer: C

Rationale: Failed to generate a rationale after 5 retries.

Correct Answer: B

Rationale: The correct answer is B: 19 protons. Potassium's atomic number is 19, which represents the number of protons in its nucleus. Protons are positively charged particles in an atom. Option A (18) is incorrect as it does not match the atomic number of Potassium. Options C (20) and D (21) are also incorrect as they do not correspond to Potassium's atomic number. Thus, the correct answer is B (19) based on the periodic table.

Correct Answer: B

Rationale: The correct answer is B: Sum of protons and neutrons. Atomic mass is the total mass of an atom, which is the combined mass of protons and neutrons in the nucleus. This value is measured in atomic mass units (amu). Choice A is incorrect because it refers to the atomic number (number of protons). Choice C is incorrect as it only considers the number of neutrons, not the total mass. Choice D is incorrect because atomic mass is not an average weight but a specific value for a single atom.

Correct Answer: B

Rationale: The correct answer is B: London dispersion force. This is because London dispersion forces are the weakest intermolecular force, resulting in lower boiling points compared to the other options. London dispersion forces are temporary, induced forces caused by momentary fluctuations in electron distribution within molecules. Dipole-dipole interactions (A), Keesom interactions (C), and hydrogen bonding (D) are stronger intermolecular forces that require specific molecular properties such as permanent dipoles or hydrogen bonding, leading to higher boiling points. Therefore, London dispersion forces would result in the lowest boiling point among the options provided.