Chemistry HESI A2 Quizlet

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: D

Rationale: The correct answer is D because fluorine, oxygen, and nitrogen are typically involved in hydrogen bonding due to their high electronegativity, which allows them to form strong partial charges. This creates a polar covalent bond with hydrogen, leading to hydrogen bonding. Fluorine, chlorine, and oxygen (Choice B) are incorrect as chlorine is not typically involved. Carbon, hydrogen, and oxygen (Choice A) lack the necessary electronegativity for hydrogen bonding. Fluorine, chlorine, and nitrogen (Choice C) also lack the required electronegativity for effective hydrogen bonding. In summary, only elements with high electronegativity like fluorine, oxygen, and nitrogen are typically involved in hydrogen bonding.

Correct Answer: B

Rationale: The correct answer is B: Solid. Solids have a definite shape and volume because the particles are closely packed and vibrate in fixed positions. Liquids (choice A) have a definite volume but not a definite shape as they take the shape of their container. Gases (choice C) have neither a definite shape nor volume as their particles are free to move around. Plasma (choice D) is a state of matter where particles are ionized, and it lacks a definite shape or volume. Therefore, the correct answer is B.

Correct Answer: B

Rationale: The correct answer is B: Double replacement. In this type of reaction, two ionic compounds swap ions to form two new compounds. The cations and anions switch partners, leading to the formation of two different ionic compounds. This process is also known as metathesis. Single replacement (A) involves an element replacing another in a compound. Synthesis (C) involves the combination of two or more substances to form a single compound. Decomposition (D) involves a single compound breaking down into simpler substances. Double replacement is the only option where two ionic compounds exchange partners, making it the correct choice in this scenario.

Correct Answer: B

Rationale: The correct answer is B: By their chemical properties. The periodic table arranges elements based on their atomic number, which determines their chemical properties. Elements in the same column have similar properties due to their shared electron configurations. This organization helps predict an element's behavior in chemical reactions. Choices A, C, and D are incorrect because atomic mass, physical state, and charge do not determine an element's position in the periodic table or its relationship to other elements.