Chemistry HESI A2 Quizlet

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.

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.

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.

Correct Answer: C

Rationale: The correct answer is C: Several feet of concrete. Gamma radiation is highly penetrating and requires dense materials to effectively block it. Concrete, being a dense material, can absorb and block gamma radiation effectively due to its high atomic number and thickness. Aluminum foil (A) and glass (B) are not dense enough to stop gamma radiation. Paper (D) is too thin and lacks the density needed to block gamma radiation effectively.

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.