HESI A2 Chemistry

Correct Answer: B

Rationale: The correct answer is B: Decomposition. In this reaction, a single reactant (AB) breaks down into two or more products (A and B). This aligns with the definition of a decomposition reaction, where a compound is broken down into simpler substances. Choice A (Synthesis) involves combining two or more substances to form a more complex product, which is not the case here. Choices C (Single replacement) and D (Double replacement) involve the exchange of ions or elements between compounds, which is not happening in the given reaction. Thus, based on the breakdown of reactants and products, the correct classification of the reaction is decomposition.

Correct Answer: C

Rationale: Failed to generate a rationale after 5 retries.

Correct Answer: D

Rationale: The correct answer is D, H₂O. Water (H₂O) contains a polar covalent bond. This is because oxygen is more electronegative than hydrogen, creating an unequal sharing of electrons, resulting in a partial negative charge on oxygen and a partial positive charge on hydrogen. This polarity makes water a universal solvent and gives rise to properties like surface tension and hydrogen bonding. Choices A, B, and C (O, F, Br) do not form polar covalent bonds as they do not have significantly different electronegativities compared to the other element in the bond.

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: B

Rationale: The correct answer is B: Beta radiation. Beta radiation consists of high-energy electrons or positrons traveling at high speeds, typically around 16,000 km/sec. This is because beta particles are emitted during the decay of a radioactive nucleus when a neutron changes into a proton and an electron (beta-minus decay) or a proton changes into a neutron and a positron (beta-plus decay). Alpha radiation (A) consists of helium nuclei, gamma radiation (C) is high-energy electromagnetic radiation, and there is no such thing as delta radiation (D) in the context of nuclear physics.