Chemistry HESI A2 Quizlet

Correct Answer: B

Rationale: The correct answer is B: 0. Noble gases have a full outer electron shell, making them stable and unreactive. This full shell means they do not gain or lose electrons, so they have no overall charge, making their charge 0. Choice A (-1) is incorrect because it indicates gaining an electron to achieve a full outer shell, which is not characteristic of noble gases. Choices C (1) and D (2) are incorrect as they suggest a positive charge, which noble gases do not possess due to their stable electron configuration.

Correct Answer: B

Rationale: The correct answer is B: Alpha. Alpha radiation involves the emission of helium ions, which are essentially helium atoms that have lost two electrons. This type of radiation consists of alpha particles, which are positively charged and relatively heavy. They have low penetration power and can be stopped by a sheet of paper or human skin. Beta radiation (choice A) involves the emission of high-energy electrons or positrons, not helium ions. Gamma radiation (choice C) consists of electromagnetic waves and does not involve the emission of particles. There is no radiation type known as Delta (choice D). Therefore, the correct answer is B as it accurately describes the characteristics of alpha radiation.

Correct Answer: C

Rationale: The correct answer is C: Atomic number. The atomic number represents the number of protons an element has in its nucleus. This is a fundamental property of an element and determines its identity on the periodic table. Atomic mass (A) is the total combined mass of protons and neutrons in an atom. Mass number (B) is the sum of protons and neutrons in the nucleus. Neutron number (D) is the number of neutrons in an atom, which can vary for isotopes of the same element. Therefore, the atomic number is the specific number of protons in an element, making it the correct choice.

Correct Answer: A

Rationale: The correct answer is A: Neutrons. Neutrons are neutral particles because they have no charge, unlike protons (positively charged), electrons (negatively charged), and cations (positively charged ions). Neutrons are found in the nucleus of an atom along with protons, contributing to the atomic mass without affecting the overall charge. This makes them essential for maintaining the stability of the nucleus. Therefore, neutral particles are called neutrons.

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.