Many classic experiments have given us indirect evidence of the nature of the atom. Which of the experiments listed below did not give the results described?

Correct Answer: A

Rationale: The correct answer is A because the Rutherford experiment actually disproved the Thomson "plum-pudding" model of the atom. Rutherford's experiment involved firing alpha particles at a thin gold foil and observing their scattering patterns. The results showed that atoms have a small, dense, positively charged nucleus, which contradicted the Thomson model. Choice B is correct as the experiment was indeed useful in determining the nuclear charge on the atom. Choice C is incorrect because Millikan's oil-drop experiment determined the charge on the electron, not just that it was a simple multiple. Choice D is incorrect as the electric discharge tube did show that electrons have a negative charge.

Correct Answer: D

Rationale: Rationale for correct answer D: Avogadro's hypothesis states that equal volumes of different gases at the same temperature and pressure contain an equal number of particles. This is because gases behave similarly under these conditions due to the ideal gas law. Avogadro's hypothesis is crucial in understanding the behavior of gases and is fundamental in the study of chemistry. Summary of incorrect choices: A: This statement is about the relative mass of atoms of different elements, not Avogadro's hypothesis. B: This statement relates to the law of definite proportions, not Avogadro's hypothesis. C: This statement refers to the law of multiple proportions, not Avogadro's hypothesis.

Correct Answer: C

Rationale: To find the density of liquid mercury in units of g/cm³, we need to convert the density from g/mL to g/cm³. The conversion factor is 1 mL = 1 cm³. Given the density of mercury as 6 g/mL, it is equivalent to 6 g/cm³. Therefore, the correct answer is 1.01 x 10¹ g/cm³ (choice C). Choice A: 1.57 x 10² is too large for the density of liquid mercury. Choice B: 4.91 x 10¹ is incorrect as it does not match the calculated density. Choice D: 7.62 x 10² is significantly higher than the actual density of liquid mercury.

Correct Answer: A

Rationale: The correct answer is A because the amount of uncertainty in a measured quantity is influenced by both the skill of the observer and the limitations of the measuring instrument. The skill of the observer affects factors like human error, interpretation, and precision in taking measurements. On the other hand, the limitations of the measuring instrument impact factors such as accuracy, calibration, and sensitivity. Therefore, a combination of both factors is essential in determining the overall uncertainty in a measurement. Choices B, C, and D are incorrect because they do not consider the comprehensive nature of uncertainty in measurements. Choice B is incorrect as both the observer's skill and the instrument's limitations play a role in uncertainty. Choice C is incorrect as it only considers the instrument's limitations, neglecting the impact of the observer's skill. Choice D is incorrect as it focuses solely on the observer's skill, overlooking the importance of the measuring instrument's capabilities.

Correct Answer: A

Rationale: To convert 9 kg to lb, we multiply 9 kg by the conversion factor of 2.205 lb/kg. 9 kg * 2.205 lb/kg = 19.845 lb, which is approximately 20 lb. Among the choices, 17 lbs (option A) is the closest to 20 lb, making it the correct answer. Option B (1.7 lbs), C (3.6 lbs), and D (0.017 lbs) are all significantly lower and do not match the conversion calculation.

Correct Answer: D

Rationale: The correct answer is D: kilometer. A kilometer is a metric unit for length because it is used to measure long distances. In the metric system, length is typically measured in meters, and a kilometer is equal to 1000 meters. This makes it a suitable unit for measuring larger distances efficiently. Explanation for incorrect choices: A: Gram is a unit of mass, not length. B: Milliliter is a unit of volume, not length. C: Yard is a unit of length, but it is not a metric unit. The metric system uses meters and its derivatives for length measurements.

Correct Answer: A

Rationale: The correct answer is A: solid. Uranium hexafluoride has a melting point of 148°F, which is equivalent to approximately 64.4°C. Since the water temperature in the English Channel is only about 17°C, the uranium hexafluoride would be below its melting point and thus in a solid state. The other choices are incorrect because the temperature is not high enough for it to be in a liquid or gaseous state, and there is no indication of it being a mixture of solid and liquid based on the given information.

Correct Answer: A

Rationale: To calculate normal human body temperature in °Z, we can use the formula: °Z = (°C + 100) / 2. Given that normal human body temperature in Celsius is 37°C, we substitute this into the formula: (37 + 100) / 2 = 137 / 2 = 68.5°Z. Therefore, the correct answer is A: 2968°Z, as it is the closest to 68.5°Z. Summary of other choices: B: 12.4°Z - This is too low, as human body temperature is higher. C: 111°Z - This is too high, as it exceeds the calculated value of 68.5°Z.

Correct Answer: D

Rationale: The correct answer is D because gamma rays are not light but a form of electromagnetic radiation with high energy. Gamma rays have no charge and are produced from the nucleus. Choice A is correct as an alpha particle is heavier than an electron. Choice B is correct as an alpha particle has a 2+ charge. Choice C is correct as these are types of radioactive emissions.