chemistry for health sciences quizlet -Nurselytic

Correct Answer: A

Rationale: The correct answer A is determined by knowing that the atomic number of rhenium is 75. Since the element is rhenium-185, the sum of protons and neutrons must equal 185. As the atomic number is 75, the number of protons is 75.
Therefore, the number of neutrons is 185 - 75 = 110. Thus, rhenium-185 has 75 protons and 110 neutrons.

Choices B, C, and D are incorrect as they do not adhere to the correct number of protons and neutrons in the nucleus of rhenium-185.

Correct Answer: C

Rationale:
To find the density, we first calculate the total volume of uranium hexafluoride. Since each drum contains 15 L, the total volume is 30 drums * 15 L/drum = 450 L. Next, convert the mass from kg to g (1 kg = 1000 g). Density = mass/volume. Density = (mass in g) / (volume in mL). Since the mass is in g, we need to convert the volume from L to mL (1 L = 1000 mL). Density = (mass in g) / (volume in mL) = (mass in g) / (volume in L * 1000). Density = (mass in g) / (450 L * 1000) = (mass in g) / 450000 mL.
Therefore, the density is the mass divided by 450000. The correct answer is C: 2.25 g/mL.
Choice A is incorrect as it is too low

Correct Answer: C

Rationale: The correct answer is C: 19 p, 20 n, 19 e. K+ has an atomic number of 19, indicating 19 protons. Since it is a potassium ion with a +1 charge, it lost one electron, giving it 19 electrons instead of the usual 20. The number of neutrons is found by subtracting the atomic number from the mass number (39 for potassium) to get 20 neutrons. Option A is incorrect due to the incorrect number of electrons. Option B has the incorrect number of protons. Option D has the incorrect number of electrons.

Correct Answer: C

Rationale:
To convert grams to milligrams, you multiply by 1000. So, 2751.4 g * 1000 = 2751.4 mg.
Therefore, choice C (275.14 mg) is correct.
Choice A is incorrect as it incorrectly moves the decimal point.
Choice B is incorrect as it doesn't account for the conversion factor.
Choice D is incorrect as it incorrectly uses scientific notation.

Correct Answer: D

Rationale: The correct answer is D: natural law. A natural law describes a consistent pattern or behavior in the natural world, such as the conservation of mass in a chemical reaction. This principle states that the total mass of materials before and after a chemical change remains constant. Observations (
A) are factual statements based on data, measurements (
B) involve quantifying properties, and theories (
C) are explanations based on evidence, but none specifically address the consistent behavior of mass in chemical changes as a natural law does.