Chemistry HESI A2 Quizlet

Correct Answer: C

Rationale: Step-by-step rationale for why choice C (Aluminum foil) is correct: 1. Beta radiation particles are high-energy electrons or positrons. 2. Aluminum foil has a high atomic number and density, making it effective at stopping beta particles. 3. The electrons in the aluminum atoms interact with the beta particles, causing them to lose energy and stop. 4. Being thin and dense, aluminum foil can effectively block beta radiation particles. Summary of why other choices are incorrect: A. Plastic: Plastic is not dense enough to effectively stop beta particles. B. Glass: While glass is denser than plastic, it is not as effective as aluminum foil in stopping beta radiation. D. Concrete: Concrete is dense, but it is not as effective as aluminum foil in stopping beta particles due to its composition and thickness.

Correct Answer: B

Rationale: The correct answer is B: Weak. Dipole attraction is a type of intermolecular force where polar molecules are attracted to each other due to the positive and negative ends of their dipoles. This force is relatively weaker compared to other intermolecular forces like hydrogen bonding or ion-dipole interactions. It is weaker because it only involves the partial charges on molecules and not full charges like in ionic interactions. Choices A, C, and D are incorrect because dipole attractions are not as strong as those intermolecular forces that involve full charges or hydrogen bonding.

Correct Answer: A

Rationale: Certainly! The correct answer is A: Radioactivity. Radioactivity refers to the emission of particles from an unstable nucleus due to nuclear instability. This process can include alpha, beta, or gamma decay. Choice B, Radiation, is a more general term that encompasses various types of energy emission, not specific to nuclear decay. Choice C, Decay, is a broader term and does not specify the emission from a nucleus. Choice D, Fusion, involves combining nuclei to form a heavier nucleus, not the emission of particles from an unstable nucleus.

Correct Answer: A

Rationale: The correct answer is A: Hydrogen and oxygen. Water decomposes into hydrogen and oxygen through a process called electrolysis. In this process, an electric current is passed through water, causing it to break down into its constituent elements. Hydrogen is produced at the cathode, while oxygen is produced at the anode. This is a well-known and scientifically proven reaction. Choices B, C, and D are incorrect because water does not decompose into carbon dioxide, nitrogen, or methane under normal conditions. This can be confirmed by studying the chemical properties and reactions of water.

Correct Answer: B

Rationale: The correct answer is B: Physical. When no change is made to the chemical composition of a substance, it indicates a physical change. In physical changes, the substance retains its chemical identity and only its physical properties, such as shape, size, and state, are altered. This is because the particles in the substance rearrange or move without forming new substances. Choice A (Chemical) involves a change in the chemical composition, so it is incorrect. Choice C (Nuclear) involves changes at the atomic level, leading to different elements, which is not the case here. Choice D (Mechanical) involves changes in position and motion of objects, not relevant to the chemical composition of a substance.