chemistry for health sciences

Correct Answer: C

Rationale: The correct answer is C: precision. Precision refers to the degree of agreement among repeated measurements of the same quantity. It reflects how close the measurements are to each other, indicating reproducibility. Accuracy (choice A) is about how close a measurement is to the true value, not the agreement among multiple measurements. Error (choice B) is a deviation from the true value and not specifically related to the agreement among measurements. Significance (choice D) is about the importance or relevance of a result, not the consistency of measurements. Therefore, precision is the most appropriate term in this context.

Correct Answer: A

Rationale: To convert Celsius to Fahrenheit, use the formula: �F = (�C � 9/5) + 32. Plug in -2 for �C: �F = (-2 � 9/5) + 32 = -3.6 + 32 = 28.4�F. Therefore, -2�C is equal to 28.4�F. The only option close to this is A: -86.8�F, which is the correct answer. Option B (-119�F) and D (119�F) are incorrect as they are not within the correct range based on the conversion formula. Option C (-54.8�F) is also incorrect as it does not match the calculated value of 28.4�F for -2�C.

Correct Answer: A

Rationale: The correct answer is A. The plot of total mass versus volume should be rather linear because the slope measures the density of a liquid. This is because density is defined as mass divided by volume (density = mass/volume). Therefore, when mass is plotted against volume, the slope of the line represents the density of the liquid. A linear relationship between mass and volume indicates that the density remains constant. Summary of other choices: B: The plot being curved upward due to slope measuring density is incorrect. C: The plot being curved upward due to mass being higher in successive trials is incorrect. D: The plot being linear because the mass of the beaker stays constant is incorrect.

Correct Answer: A

Rationale: The correct answer is A: accuracy. Accuracy refers to how close a measured value is to the true value. It indicates the absence of systematic errors. Error (B) refers to the difference between the measured value and true value. Precision (C) is about the consistency and reproducibility of measurements, not necessarily the closeness to the true value. Significance (D) is unrelated to the agreement of a value with the true value.

Correct Answer: A

Rationale: The correct answer is A: Ions are formed by adding or removing protons or electrons. This statement is true because ions are formed when an atom gains or loses one or more electrons, resulting in a positive or negative charge. This process does not involve changing the number of protons in the nucleus. Choice B is incorrect because solids are composed of closely packed atoms or molecules, not open space. Choice C is incorrect because heating water with a Bunsen burner does not result in a 2:1 mixture of hydrogen and oxygen gases, but rather breaks down water into hydrogen and oxygen molecules. Choice D is incorrect as only statement A is true.