Chemistry HESI A2 Quizlet

Correct Answer: D

Rationale: The correct answer is D: Color of the reactants. The color of the reactants does not affect the reaction rate as it is a purely visual characteristic and does not influence the speed at which the reaction occurs. Temperature affects reaction rate by providing energy for molecules to react faster. Surface area influences reaction rate by increasing the area of contact between reactants. Concentration of reactants affects reaction rate by increasing the frequency of collisions between molecules. In summary, factors like temperature, surface area, and concentration directly impact reaction rate, whereas color is merely a visual property and does not play a role in determining the speed of a chemical reaction.

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.

Correct Answer: C

Rationale: The correct answer is C, atomic number. The atomic number represents the number of protons in an element. This is because the atomic number is the unique identifier of an element and determines its chemical properties. Protons are the positively charged particles in the nucleus of an atom, and the number of protons defines the element's identity. Explanation for incorrect choices: A: Atomic mass represents the average mass of all isotopes of an element, not the number of protons. B: Mass number is the sum of protons and neutrons in an atom, not just the number of protons. D: "Proton number" is not a standard term in chemistry, and it does not specifically refer to the number of protons in an element.

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: C

Rationale: The correct answer is C: Covalent bonds are the strongest type of chemical bond. In covalent bonds, atoms share electrons, creating a strong bond between them. This sharing of electrons results in a stable molecular structure. Ionic bonds (choice A) are strong but not as strong as covalent bonds because they involve the transfer of electrons, leading to weaker attractions. Hydrogen bonds (choice B) are weaker than covalent bonds as they are formed between hydrogen atoms and highly electronegative atoms like oxygen or nitrogen. Metallic bonds (choice D) are not as strong as covalent bonds because they involve the sharing of electrons among a sea of delocalized electrons in metals, leading to a weaker bond compared to covalent bonds.