chemistry for health sciences

Correct Answer: D

Rationale: To convert cm3 to liters, divide by 1000 as 1 liter = 1000 cm3. Therefore, 781.2 cm3 � 1000 = 0.7812 L. Correct answer is D: 0.7812 L. Other choices are incorrect as they do not reflect the correct conversion from cm3 to liters.

Correct Answer: B

Rationale: The correct answer is B: Alpha particles greatly deflected by the metal foil. In the Thomson model, the atom was thought to be a uniform, positively charged sphere. If this model had been correct, alpha particles would have passed through the foil with little or no deflection. However, Rutherford observed significant deflections, indicating a concentrated positive charge at the center (nucleus). This aligns with the concept of the Rutherford model of the atom. Choices A, C, and D are incorrect because they do not correspond to the experimental observations made by Rutherford.

Correct Answer: B

Rationale: The correct answer is B (5 significant figures) because leading zeros are not considered significant. In the number 04560700, the zeros before the 4 are placeholders and do not add to the precision of the number. Therefore, only the digits 4, 5, 6, 0, and 7 are significant. Choice A (4) is incorrect because it does not account for the zeros after the 6. Choice C (7) is incorrect as it counts all the digits including the leading zeros. Choice D (8) is incorrect as it includes all the digits, including non-significant zeros.

Correct Answer: A

Rationale: The correct answer is A: observation. Observations are specific instances of behavior that can be described and formulated into statements, including mathematical ones. Measurements (choice B) involve quantifying observations. Theories (choice C) are broader explanations based on observations. Natural laws (choice D) are general principles derived from consistent observations. In this context, the term "observed behavior" specifically points to the act of witnessing and formulating statements about behavior, making choice A the most suitable option.

Correct Answer: B

Rationale: To determine the significant figures in the difference between 6172 mL and 57 mL, subtract the numbers: 6172 mL - 57 mL = 6115 mL. The answer should have the same number of decimal places as the number with the fewest decimal places in the subtraction, which is 57 mL. Hence, the correct answer is 2 significant figures. Choice A is incorrect because it is too low as it does not account for the 1 in the tens place of 57 mL. Choice C is incorrect as it is too high because the answer does not have that many significant figures. Choice D is incorrect as it also overestimates the number of significant figures in the difference.