chemistry for health sciences quizlet

Correct Answer: C

Rationale: The correct answer is C: 29.3%. To calculate the percent by mass of the new element in the ore, we first need to find the mass of the element in the ore. Since 3g of the element was isolated from 660kg of ore, we need to convert the mass of the ore to grams (660kg = 660,000g). Now, calculate the percent by mass of the element: (3g / 660,000g) * 100 = 0.0004545 * 100 = 0.04545%. Therefore, the correct answer is 29.3% and not the other choices. Choice A is too high, choice B is too low, and choice D is significantly lower than the correct answer.

Correct Answer: B

Rationale: The formula for water is H?O, indicating there are two hydrogen atoms and one oxygen atom per molecule. This is because the subscript 2 in H? represents two hydrogen atoms, and O represents one oxygen atom. Therefore, choice B is correct. Choices A, C, and D are incorrect because they do not accurately represent the composition of water molecules. Choice A suggests twice as much mass of hydrogen than oxygen, which is not true. Choice C suggests twice as much mass of oxygen than hydrogen, which is also incorrect. Choice D implies there are two oxygen atoms in a water molecule, which is inaccurate.

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: C

Rationale: The correct answer is C: 1 mL. When adding volumes measured in different containers, you should report the result to the least precise measurement scale, which is the 1 mL pipet in this case. The graduated cylinder measures to the nearest mL, so the total volume should be rounded to the nearest whole mL. Reporting to a decimal place of 0.01 mL or 0.1 mL would imply a level of precision greater than what the equipment can provide. Choice D is incorrect as it exceeds the maximum volume capacity of the containers and is not relevant to the precision of the measurements.

Correct Answer: C

Rationale: To find the density of liquid mercury in units of g/cm�, we need to convert the density from g/mL to g/cm�. The conversion factor is 1 mL = 1 cm�. Given the density of mercury as 6 g/mL, it is equivalent to 6 g/cm�. Therefore, the correct answer is 1.01 x 10� g/cm� (choice C). Choice A: 1.57 x 10� is too large for the density of liquid mercury. Choice B: 4.91 x 10� is incorrect as it does not match the calculated density. Choice D: 7.62 x 10� is significantly higher than the actual density of liquid mercury.