ATI RN
chemistry for health sciences Questions
Question 1 of 5
409 Kelvin equals
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.
Question 2 of 5
All of the following are true except:
Correct Answer: B
Rationale: The correct answer is B because changing the number of protons in an atom's nucleus would result in a different element, not an ion. A: True - adding or removing electrons forms ions. C: True - removing electrons forms positively charged ions. D: True - ions have a charge due to the imbalance of protons and electrons.
Question 3 of 5
The first scientist to show that atoms emit any negative particles was
Correct Answer: A
Rationale: Step-by-step rationale: 1. J.J. Thomson discovered the electron in 1897 through his cathode ray experiment. 2. Electrons are negatively charged particles emitted by atoms. 3. This groundbreaking discovery proved atoms emit negative particles. 4. Therefore, J.J. Thomson is the correct answer. Summary: - Lord Kelvin focused on thermodynamics, not subatomic particles. - Ernest Rutherford discovered the nucleus, not electrons. - William Thomson, also known as Lord Kelvin, did not directly contribute to the discovery of negative particles emitted by atoms.
Question 4 of 5
A scientist obtains the number 0.045006700 on a calculator. If this number actually has four significant figures, how should it be written?
Correct Answer: C
Rationale: The correct answer is C: 0.045. When dealing with significant figures, trailing zeros after the decimal point are considered significant. In this case, the number 0.045006700 should be rounded to 0.045 since it has four significant figures. Choice A has too many significant figures, B rounds incorrectly, and D removes significant figures after the decimal point. Thus, C is the correct choice.
Question 5 of 5
The melting point of indium is 2°C. At 323°F, what is the physical state of indium?
Correct Answer: B
Rationale: To determine the physical state of indium at 323°F, we convert the temperature to Celsius (323°F = 161.7°C). Since the melting point of indium is 2°C, which is lower than 161.7°C, indium would be in a liquid state at 323°F. The correct choice is B: Liquid. A: Solid - Incorrect because indium is in a liquid state at 323°F. C: Gas - Incorrect, as indium would be in a liquid state at 323°F. D: Not enough information - Incorrect since the temperature provided allows us to determine the physical state of indium.