Chemistry HESI A2 Quizlet

Correct Answer: B

Rationale: The correct answer is B: Ionic & covalent. Ionic bonding involves the transfer of electrons between atoms, resulting in the formation of positive and negative ions. Covalent bonding involves the sharing of electrons between atoms. These two types of bonding are distinct in their electron behavior and resulting bond strength. Choice A is incorrect as hydrogen bonding is a type of intermolecular force, not a primary chemical bond. Choice C is incorrect as hydrogen bonding is not a primary chemical bond and ionic bonding involves the transfer of electrons, not hydrogen atoms. Choice D is incorrect as metallic bonding involves the sharing of electrons in a sea of electrons, not between specific atoms.

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: C

Rationale: The correct answer is C: Combustion. Combustion is a chemical reaction where a compound reacts with oxygen to produce heat, light, and often carbon dioxide and water. In this type of reaction, oxygen is a reactant and typically a hydrocarbon or organic compound is the fuel. Decomposition involves a compound breaking down into simpler substances, synthesis is when two or more substances combine to form a more complex compound, and single replacement is when one element replaces another in a compound. Combustion specifically involves the reaction with oxygen, making it the correct choice in this scenario.

Correct Answer: A

Rationale: The correct answer is A: 1. In a single bond, only one pair of electrons is shared between two atoms, resulting in a stable bond. This shared pair of electrons creates a strong attraction between the atoms, holding them together. The other choices (B, C, D) are incorrect as they represent the number of pairs of electrons shared in double, triple, or quadruple bonds, respectively, which involve 2, 3, or 4 pairs of electrons being shared, not in a single bond. Thus, the correct answer is A because a single bond involves only one pair of shared electrons.

Correct Answer: B

Rationale: The correct answer is B (-2). Group VIA elements, also known as Chalcogens, have 6 valence electrons. They typically gain 2 electrons to achieve a stable octet configuration, resulting in a -2 charge. Option A (-1) is incorrect because gaining 1 electron would not complete the octet. Option C (-3) is incorrect because gaining 3 electrons is energetically unfavorable. Option D (0) is incorrect because Group VIA elements tend to gain electrons to achieve stability.