Chemistry HESI A2 Quizlet

Correct Answer: C

Rationale: The correct answer is C: +2. Alpha radiation particles are helium nuclei consisting of 2 protons and 2 neutrons, giving them a charge of +2. This charge is due to the presence of 2 protons, which are positively charged particles. Choice A (-2) is incorrect as alpha particles are positively charged. Choice B (0) is incorrect as alpha particles have a positive charge. Choice D (+1) is incorrect as alpha particles have a charge of +2 due to the presence of 2 protons.

Correct Answer: D

Rationale: The correct answer is D: Molar mass. One mole of a substance represents the molar mass, which is the mass of one mole of that substance in grams. This is calculated by summing the atomic masses of all the atoms in the chemical formula. The molar mass is expressed in g/mol and is a fundamental concept in chemistry for performing various calculations. A: Atomic mass refers to the mass of an individual atom of an element, not one mole of a substance. B: Mass number refers to the total number of protons and neutrons in an atom's nucleus, not the mass of one mole of a substance. C: Molecular weight is the sum of the atomic weights of the atoms in a molecule, not the mass of one mole of a substance.

Correct Answer: B

Rationale: The correct answer is B: Gas. Gases change in volume with changes in temperature and pressure according to the ideal gas law (PV = nRT). When temperature or pressure increases, gas molecules move faster and occupy more space, leading to an increase in volume. Liquids (choice A) have relatively fixed volumes, solids (choice C) have definite shapes and volumes, and plasmas (choice D) are ionized gases with unique properties but still do not change volume based on temperature and pressure changes.

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: B

Rationale: The correct answer is B because hydrogen bonding, dipole interactions, and dispersion forces are the three types of intermolecular forces. Hydrogen bonding occurs between molecules with a hydrogen atom bonded to a highly electronegative atom. Dipole interactions arise from the attraction between polar molecules. Dispersion forces are the weakest intermolecular forces and occur due to temporary fluctuations in electron distribution. Choices A, C, and D are incorrect because they do not accurately represent the three specific types of intermolecular forces.