Different isotopes of a particular element contain the same number of

Correct Answer: A

Rationale: Different isotopes of a particular element contain the same number of protons. Isotopes are defined by the number of neutrons they have, which can vary while the number of protons remains the same. This is because the number of protons in an atom determines its elemental identity. Choice B - Neutrons is incorrect because isotopes can have different numbers of neutrons. Choice C - Protons and neutrons is incorrect because the number of neutrons can vary in isotopes. Choice D - Protons, neutrons, and electrons is incorrect because electrons are not fixed and can vary in an atom, but the number of protons is what defines the element.

Correct Answer: C

Rationale: The English scientist who made accurate observations on how pressure and volume are related was Robert Boyle. Boyle's law states that the pressure of a gas is inversely proportional to its volume when the temperature is constant. This fundamental gas law was discovered by Robert Boyle in the 17th century and laid the groundwork for our understanding of the behavior of gases. Choices A, B, and D are incorrect. Charles refers to Charles's law, not Boyle. Combine is not related to the topic, and Gay-Lussac is associated with Gay-Lussac's law, not Boyle's law.

Correct Answer: A

Rationale: Real gases approach ideal behavior at high pressure and high temperature. At these conditions, the volume of the gas molecules becomes negligible compared to the total volume of the gas. Additionally, the average distance between molecules becomes small enough for intermolecular forces to become less significant, leading to behavior that closely mirrors the assumptions of the ideal gas law. Choice B is incorrect because low pressure does not favor ideal behavior as the volume of gas molecules becomes more significant. Choice C is incorrect as the boiling point of water does not directly relate to ideal gas behavior. Choice D is incorrect because real gases can approach ideal behavior under specific conditions, such as high pressure and high temperature.

Correct Answer: C

Rationale: Charles' Law states that the volume of a gas is directly proportional to its absolute temperature at constant pressure. This means that as the temperature of a gas increases, its volume also increases proportionally, and vice versa. This relationship between temperature and volume is a key feature of Charles' Law. The Combined Gas Law involves the relationships between pressure, volume, and temperature of a gas. Boyle's Law describes the inverse relationship between the pressure and volume of a gas at constant temperature. The Ideal Gas Law combines Boyle's Law, Charles' Law, and Avogadro's Law into a single expression. Therefore, the correct answer is Charles' Law, as it specifically describes the direct relationship between the temperature and volume of a gas.

Correct Answer: B

Rationale: Oxygen typically has an oxidation number of -2 in compounds because it tends to gain electrons. This is due to its high electronegativity, which leads to oxygen attracting electrons towards itself in a chemical bond. Choice A (2) is incorrect because oxygen doesn't have a +2 oxidation number in compounds. Choice C (0) is incorrect as oxygen rarely has an oxidation number of 0 in compounds. Choice D (-1) is incorrect as oxygen's oxidation number in compounds is typically -2, not -1.