HESI A2
HESI A2 Chemistry Questions Questions
Question 1 of 5
What is the name of the negatively charged subatomic particles?
Correct Answer: C
Rationale: The correct answer is C: Electrons. Electrons are the negatively charged subatomic particles. They are found outside the atomic nucleus and carry a negative charge. Protons are positively charged particles found in the nucleus, neutrons have no charge, and isotopes are atoms of the same element with different numbers of neutrons, not subatomic particles.
Question 2 of 5
What is a benefit of water's ability to make hydrogen bonds?
Correct Answer: D
Rationale: The correct answer is D, high specific heat. Water's ability to form hydrogen bonds results in a high specific heat capacity, allowing it to absorb and release a large amount of heat energy with minimal temperature change. This property is essential for moderating temperature changes in organisms and maintaining stable environmental conditions for life processes.
Choices A, lack of cohesiveness, and C, use as a nonpolar solvent, are incorrect. Water actually has high cohesiveness due to its ability to form hydrogen bonds, and it is a polar solvent, not nonpolar.
Choice B, low surface tension, is also incorrect as water's hydrogen bonding contributes to its relatively high surface tension.
Question 3 of 5
Which of the following elements is a noble gas?
Correct Answer: C
Rationale: The correct answer is C: Argon. Argon is a noble gas, part of Group 18 in the periodic table. Noble gases are colorless, odorless, and typically non-reactive under normal conditions. Other elements in this group include helium, neon, krypton, xenon, and radon. Argon finds wide applications in welding, lighting, and scientific research.
Choices A, B, and D are not noble gases. Hydrogen is a non-metal, Fluorine is a halogen, and Nitrogen is a diatomic non-metal gas.
Question 4 of 5
What is the SI unit of energy?
Correct Answer: B
Rationale: The SI unit of energy is the 'joule'. The joule is defined as the work done when a force of one newton acts over a distance of one meter. It is the standard unit used to measure energy in the International System of Units (SI).
Therefore, the correct answer is 'joule.'
Choice A, 'ohm,' is the SI unit of electrical resistance, not energy.
Choice C, 'henry,' is the SI unit of inductance, not energy.
Choice D, 'newton,' is the SI unit of force, not energy. Hence, they are all incorrect in the context of measuring energy.
Question 5 of 5
What is the pH of a neutral solution?
Correct Answer: A
Rationale: The correct answer is A: 7. A neutral solution has a pH of 7. In the pH scale, values below 7 are acidic, 7 is neutral, and values above 7 are basic.
Therefore, a solution with a pH of 7 is considered neutral as it is neither acidic nor basic.
Choices B, C, and D are incorrect because a pH of 0 indicates a strong acid, a pH of 14 indicates a strong base, and a pH of 4 indicates an acidic solution. None of these values represent a neutral solution.