HESI A2 Chemistry Questions

Correct Answer: A

Rationale: The correct answer is A: Uranium. Uranium has the highest atomic number among the options provided. Atomic number represents the number of protons in the nucleus of an atom. Uranium has an atomic number of 92, which is higher than the other elements listed. Hydrogen has an atomic number of 1, Radon has an atomic number of 86, and Bismuth has an atomic number of 83. Therefore, Uranium has the highest atomic number, making it the correct choice.

Correct Answer: C

Rationale: The correct answer is C: Ammonia. Ammonia is a base because it can accept protons (H+ ions) to form ammonium ions (NH4+). It can also react with water to form ammonium hydroxide, which is a strong base. Water (choice A) is neutral, not a base. Sodium chloride (choice B) is a salt formed from the reaction of a strong acid and a strong base, not a base itself. "Salt" (choice D) is a general term for any ionic compound formed from the neutralization of an acid and a base, not specifically a base.

Correct Answer: B

Rationale: The correct answer is B: Oxygen. During photosynthesis, plants use carbon dioxide and water to produce glucose and oxygen. Oxygen is released as a byproduct of this process through the stomata in plant leaves. Carbon dioxide (A) is actually used up during photosynthesis, not released. Nitrogen (C) and Helium (D) are not involved in the process of photosynthesis.

Correct Answer: D

Rationale: The correct answer is D: Glucose. Glucose is a product of photosynthesis, as plants use sunlight, water, and carbon dioxide to produce glucose (sugar) and oxygen. Glucose is a type of carbohydrate that serves as a primary source of energy for plants and other organisms. Carbon dioxide (A) is one of the reactants needed for photosynthesis, not a product. Oxygen (B) is released as a byproduct of photosynthesis, not a product. Water (C) is also a reactant in photosynthesis, not a product. Therefore, the correct answer is D because glucose is the main product of photosynthesis.

Correct Answer: B

Rationale: The correct answer is B: Neon. Noble gases are a group of elements that are inert and have a full outer electron shell, making them stable and unreactive. Neon belongs to the noble gas group in the periodic table, with a full outer electron shell, making it stable. Oxygen (A) is a reactive nonmetal, hydrogen (C) is a nonmetal but not a noble gas, and argon (D) is also a noble gas but not the correct answer in this case.