Chemistry HESI A2 Quizlet

Correct Answer: C

Rationale: The columns of the periodic table are called "Groups" because elements within the same group share similar chemical properties due to having the same number of valence electrons. Each group is designated by a number and a letter, indicating the number of valence electrons. Periods refer to the rows of the periodic table, representing the number of electron shells an element has. Families is a more colloquial term used to describe groups of elements with similar properties. Rows refer to the horizontal rows of the periodic table. Therefore, the correct answer is C as it specifically refers to the vertical columns in the periodic table that share similar chemical properties.

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.

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: C

Rationale: Increasing the surface area of a reactant increases the number of exposed particles available for collision, leading to more frequent and successful collisions. This results in an increased reaction rate. Choice A is incorrect because more surface area facilitates faster reactions. Choice B is incorrect as surface area affects reaction rate. Choice D is incorrect as increasing surface area does not stop the reaction; it actually accelerates it.

Correct Answer: B

Rationale: The correct answer is B: Nuclear. Nuclear reactions involve changes in the nucleus of an atom, such as nuclear fusion or fission, to achieve stable nuclear configurations by balancing the number of protons and neutrons. Chemical reactions (Choice A) involve changes in electron configurations, not the nucleus. Physical reactions (Choice C) involve changes in state or structure, not nuclear configurations. Mechanical reactions (Choice D) involve forces and motion, not changes in the nucleus for stability. Therefore, option B is the correct choice for reactions taking place in the nucleus to achieve stable nuclear configurations.