Chemistry HESI A2 Quizlet

Correct Answer: A

Rationale: Step-by-step rationale: 1. Combustion of hydrocarbons involves reaction with oxygen. 2. Hydrocarbons contain only carbon and hydrogen atoms. 3. Complete combustion results in the formation of water (H2O) and carbon dioxide (CO2). 4. This is due to the hydrogen atoms combining with oxygen to form water and carbon atoms combining with oxygen to form carbon dioxide. 5. Therefore, the correct answer is A: Water and carbon dioxide. Summary: - Choice B is incorrect as oxygen is not a product of combustion, but a reactant. - Choice C is incorrect as hydrogen and carbon monoxide are not the typical products of hydrocarbon combustion. - Choice D is incorrect as oxygen is not a product of combustion, and carbon monoxide is not a common product of hydrocarbon combustion.

Correct Answer: C

Rationale: The Group VA elements in the periodic table belong to the nitrogen family, including nitrogen, phosphorus, arsenic, antimony, and bismuth. These elements typically have a charge of -3 because they have 5 valence electrons and tend to gain 3 electrons to achieve a stable octet configuration. This results in a 3- charge. Therefore, choice C (-3) is the correct answer. Choices A, B, and D are incorrect because Group VA elements do not typically have a charge of -1, -2, or 0 respectively based on their electron configuration and tendency to gain electrons.

Correct Answer: B

Rationale: The sum of protons and neutrons in an element represents the mass number. Protons and neutrons are located in the nucleus and contribute to the mass of an atom. The atomic number (A) is the number of protons in an atom, not the sum of protons and neutrons. Atomic mass (C) is the average mass of an element's isotopes, considering their abundance, and is not the sum of protons and neutrons. Neutron number (D) refers to the specific number of neutrons in an atom, not the total mass of the nucleus. Therefore, the correct answer is B, as it accurately represents the total mass of an atom.

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: C

Rationale: The correct answer is C: 3. In a triple covalent bond, 3 electron pairs are shared between two atoms. This results in the sharing of a total of 6 electrons, forming a strong bond. Each bond consists of one sigma bond and two pi bonds. Option A (1) is incorrect as a single bond involves one electron pair, while option B (2) is incorrect as a double bond consists of 2 electron pairs. Option D (4) is incorrect because a triple bond only involves 3 electron pairs being shared.