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: D

Rationale: To convert Kelvin to Celsius, subtract 273. So, 409K - 273 = 136°C. Choice D is correct. Choice A (136°F) is incorrect because it's a Fahrenheit conversion. Choice B (273°F) is incorrect, as it doesn't convert Kelvin to Fahrenheit. Choice C (682°F) is incorrect, as it's double the incorrect Fahrenheit conversion.

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.

Correct Answer: D

Rationale: The correct answer is D: Berzelius. Berzelius is credited with inventing symbols for elements and a system for writing compound formulas. He also discovered selenium, silicon, and thorium. Berzelius made significant contributions to the field of chemistry. A: Boyle is known for Boyle's Law related to gases, not for inventing chemical symbols or discovering elements. B: Lavoisier is known as the father of modern chemistry but did not invent chemical symbols or discover these elements. C: Priestly is known for discovering oxygen, but not for the specific contributions mentioned in the question.

Correct Answer: A

Rationale: To find the density in ounces/quart, we first need to convert the mass of glycerol to ounces. 2 grams is equal to 0.5 ounces (2 grams / 4 grams per ounce). Next, convert the volume from mL to quarts. Since 1000 mL is 1 liter and 1 liter is 0.26 quarts (1 liter / 3.78 liters per gallon / 4 quarts per gallon), 0 mL is equal to 0 quarts. Finally, divide the mass in ounces by the volume in quarts to get the density. Therefore, the density of glycerol is 0.5 oz/qt, which is equivalent to 41.9 oz/qt. Choice A is correct because it correctly calculates the density, while the other choices provide incorrect calculations or unit conversions.