Chemistry HESI A2 Quizlet

Correct Answer: B

Rationale: The correct answer is B: Neutron. Beta radiation is the product of the decomposition of a neutron undergoing beta decay. During beta decay, a neutron decays into a proton, an electron (beta particle), and an antineutrino. This process results in the emission of beta radiation. Choice A: Proton is incorrect because beta decay does not involve the decomposition of a proton. Choice C: Electron is incorrect because beta decay actually involves the emission of an electron. Choice D: Photon is incorrect because beta decay results in the emission of beta particles (electrons) and not photons.

Correct Answer: C

Rationale: The correct answer is C: Atomic mass. Atomic mass refers to the average mass of an element's isotopes as they occur in nature. This is calculated by taking into account the abundance of each isotope. The atomic number (A) is the number of protons in an atom's nucleus, not the average mass. The mass number (B) is the sum of protons and neutrons in an atom's nucleus, not the average mass. Neutron number (D) is simply the number of neutrons in an atom's nucleus, not the average mass. Therefore, the correct term for the average mass of isotopes is atomic mass.

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: A

Rationale: The Group VIIA elements, also known as the halogens, have a charge of -1. This is because they require one additional electron to achieve a stable octet configuration, making them highly reactive nonmetals. The correct answer is A (-1) because halogens readily gain one electron to fill their outer energy level. Choices B (-2) and D (1) are incorrect because the charge of Group VIIA elements is typically -1, not -2 or +1. Choice C (0) is incorrect because Group VIIA elements do not have a charge of 0; they have a tendency to gain an electron rather than lose one.

Correct Answer: A

Rationale: The correct answer is A: Periods. Periods are the horizontal rows in the periodic table that represent the number of electron shells an element has. Each period corresponds to the principal energy level of the element. Families (Choice B) are the vertical columns of the periodic table that share similar properties. Groups (Choice C) are also vertical columns that share similar chemical properties. Columns (Choice D) are not a term used in the context of the periodic table. Therefore, the correct term for the horizontal rows in the periodic table is periods.