ATI RN
chemistry for health sciences Questions
Question 1 of 5
Convert: –2°C = °F.
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.
Question 2 of 5
The degree of agreement among several measurements of the same quantity is called . It reflects the reproducibility of a given type of measurement.
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.
Question 3 of 5
Alpha particles beamed at thin metal foil may
Correct Answer: D
Rationale: The correct answer is D because when alpha particles are beamed at a thin metal foil, some pass directly through due to their small size and high energy (option
A), while others are reflected by direct contact with nuclei in the metal foil (option
C). This is based on the Rutherford scattering experiment which showed that alpha particles can be deflected by the positive nuclei in the metal foil. Option B is incorrect as alpha particles are not diverted by attraction to electrons in the foil. Option D combines the correct explanations for the behavior of alpha particles when beamed at thin metal foil.
Question 4 of 5
The density of oleic acid is 895 g / mL. What is the thickness of the monolayer (the length of an oleic acid molecule)?
Correct Answer: B
Rationale: The correct answer is B.
To calculate the thickness of the monolayer, we need to use the formula thickness = density / (Avogadro's number * molecular weight). Given the density of oleic acid (895 g/mL), we can substitute this value along with the molecular weight of oleic acid into the formula. By dividing the density by the product of Avogadro's number and the molecular weight, we obtain the thickness in cm. The other choices are incorrect because they do not consider the given density and relevant constants in the calculation.
Choice A, C, and D do not follow the correct formula for determining the thickness of the monolayer.
Question 5 of 5
Which of the following metric relationships is incorrect?
Correct Answer: B
Rationale: The correct answer is B: 1 gram = 10^3 kilograms. This is incorrect because 1 kilogram is equal to 1000 grams, not 100 grams. A is correct as 1 microliter is indeed 10^-6 liters. C is correct as 10^3 milliliters equals 1 liter. D is correct as 1 gram is equal to 10^2 centigrams. The incorrect relationship in choice B violates the metric system conversion factor of 1 kilogram being equal to 1000 grams.