Chemistry HESI A2 Practice Test - Nurselytic

Correct Answer: B

Rationale: The normal body temperature for humans is 98.6°F, which is equivalent to 37°C. This temperature is considered the average baseline for most individuals when measured orally.
Choice A (96°F) is too low for normal body temperature.
Choice C (100°F) is too high for normal body temperature.
Choice D (95°F) is also lower than the normal body temperature range.
Therefore, the correct answer is B, 98.6°F.

Correct Answer: D

Rationale: In water solutions of bases, the dominant ion would be OH⁻ (hydroxide ion). Bases release OH⁻ ions when dissolved in water, increasing the concentration of hydroxide ions and leading to a higher pH. This is in contrast to acids, which release H⁺ ions.
Therefore, in water solutions of bases, the presence of OH⁻ ions signifies the basic nature of the solution.

Choices A, B, and C are incorrect because MgCl₂ is a salt, 2HCl is a compound consisting of two hydrogen ions and one chloride ion, and H⁺ represents a hydrogen ion typically associated with acids, not bases.

Correct Answer: C

Rationale: In water, the bond formed between the oxygen atom and the hydrogen atoms is a polar covalent bond. The oxygen atom attracts the shared electrons more strongly, creating a partial negative charge on the oxygen and a partial positive charge on the hydrogen atoms. In the salt formed, the bond between the metal cation and the nonmetal anion is predominantly an ionic bond. The metal cation donates electrons to the nonmetal anion, resulting in the formation of oppositely charged ions that are held together by electrostatic attractions.

Choices A and B are incorrect because water and salts do not form bonds that are liquid and metallic, or polar and nonpolar covalent.
Choice D is incorrect as it oversimplifies the types of bonds present in water and salts, failing to differentiate between the covalent bond in water and the ionic bond in the salt.

Correct Answer: A

Rationale: The electron configuration for lithium is 1s²2s¹. Lithium has 3 electrons, and the configuration indicates that the first two electrons fill the 1s orbital, while the third electron fills the 2s orbital.
Therefore, the correct electron configuration for lithium is 1s²2s¹.
Choice B (1s²2s²) is incorrect as it represents the electron configuration for beryllium, not lithium.
Choice C (1s²2s¹2p¹) includes the 2p orbital, which is not involved in lithium's electron configuration.
Choice D (1s¹2s¹2p²) is incorrect as it does not accurately represent lithium's electron configuration.

Correct Answer: B

Rationale: When an atom gains electrons, it becomes negatively charged and is called an anion. An anion is formed when an atom gains one or more electrons, leading to an excess of negative charge.

Choice A, 'Cation,' is incorrect because a cation is formed when an atom loses electrons, resulting in a positively charged ion.
Choice C, 'Isotope,' refers to atoms of the same element with different numbers of neutrons and is not related to gaining electrons.
Choice D, 'Electron,' is the particle that an atom gains to become an anion, not the term for the atom itself after gaining electrons.