Chemistry HESI A2 Quizlet

Correct Answer: C

Rationale: Group IIIA elements have 3 valence electrons, which they tend to lose to achieve a stable octet electron configuration. By losing 3 electrons, they acquire a +3 charge. This is why the correct answer is C. Choice A is incorrect because Group IIIA elements do not typically gain electrons to have a +1 charge. Choice B is incorrect as they don't lose 2 electrons to have a +2 charge. Choice D is incorrect as they do not gain or lose electrons to have a charge of 0.

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: B

Rationale: The correct answer is B (2). In a double covalent bond, two electron pairs are shared between two atoms. This is achieved by the sharing of two pairs of electrons, resulting in a total of four electrons being shared. However, since each pair consists of two electrons, the number of electron pairs shared to form a double covalent bond is 2. Choices A, C, and D are incorrect because a double bond involves the sharing of 2 electron pairs, not 1, 3, or 4 pairs.

Correct Answer: A

Rationale: The correct answer is A: Hydrogen and oxygen. Water decomposes into hydrogen and oxygen through a process called electrolysis. In this process, an electric current is passed through water, causing it to break down into its constituent elements. Hydrogen is produced at the cathode, while oxygen is produced at the anode. This is a well-known and scientifically proven reaction. Choices B, C, and D are incorrect because water does not decompose into carbon dioxide, nitrogen, or methane under normal conditions. This can be confirmed by studying the chemical properties and reactions of water.