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: D

Rationale: Dispersion forces are the weakest intermolecular force because they are caused by temporary fluctuations in electron distribution, leading to temporary dipoles. These forces exist between all molecules, regardless of polarity. Dipole interactions are stronger as they involve permanent dipoles in polar molecules. Hydrogen bonding is even stronger, occurring between a hydrogen atom bonded to a highly electronegative atom and another electronegative atom. Van der Waals forces encompass both dipole interactions and dispersion forces. Thus, dispersion forces are the weakest intermolecular force among the given options.

Correct Answer: C

Rationale: The correct answer is C: Radiation. During radioactivity, particles such as alpha and beta particles, gamma rays, and positrons are emitted. These particles are collectively known as radiation. Electrons (choice A) and protons (choice B) are subatomic particles found in atoms and are not typically emitted during radioactivity. Neutrons (choice D) are neutral subatomic particles and are not emitted during radioactivity. Therefore, the correct answer is C as it encompasses the various types of particles emitted during radioactive decay.

Correct Answer: A

Rationale: The correct answer is A: 1. In a single bond, only one pair of electrons is shared between two atoms, resulting in a stable bond. This shared pair of electrons creates a strong attraction between the atoms, holding them together. The other choices (B, C, D) are incorrect as they represent the number of pairs of electrons shared in double, triple, or quadruple bonds, respectively, which involve 2, 3, or 4 pairs of electrons being shared, not in a single bond. Thus, the correct answer is A because a single bond involves only one pair of shared electrons.

Correct Answer: A

Rationale: The Group IA elements, also known as alkali metals, have a +1 charge. This is because they have one valence electron, which they readily lose to achieve a stable electron configuration. This results in them forming ions with a +1 charge. Therefore, the correct answer is A. Choice B (+2) is incorrect because alkali metals do not typically form ions with a +2 charge due to their tendency to lose only one electron. Choice C (+3) is also incorrect as alkali metals do not form ions with a +3 charge. Choice D (0) is incorrect because alkali metals are known for their tendency to lose electrons to achieve a stable configuration, resulting in a positive charge.