Correct Answer: A

Rationale: The correct order is A: nano- < milli- < centi- < kilo-. The rationale is as follows: 1. Start from the smallest prefix, which is nano- representing 10^-9. 2. Moving up, milli- comes next representing 10^-3, which is larger than nano-. 3. Following milli- is centi- representing 10^-2, larger than milli-. 4. Lastly, kilo- is the largest prefix representing 10^3, making it the largest of the four options. Therefore, the correct order is nano- < milli- < centi- < kilo-. The other choices are incorrect because they do not follow the correct increasing order of magnitude for the metric prefixes.

Correct Answer: A

Rationale: The correct answer is A because it involves a measurable quantity (length) that can be expressed numerically. This is a quantitative observation as it can be described with numbers. Choices B and C describe qualities (color and appearance) which are qualitative observations. Choice D provides a quantitative measurement (temperature) but it is not an observation, rather a measurement.

Correct Answer: A

Rationale: The correct order is A: nano- < milli- < centi- < kilo-. The rationale is as follows: 1. Start from the smallest prefix, which is nano- representing 10^-9. 2. Moving up, milli- comes next representing 10^-3, which is larger than nano-. 3. Following milli- is centi- representing 10^-2, larger than milli-. 4. Lastly, kilo- is the largest prefix representing 10^3, making it the largest of the four options. Therefore, the correct order is nano- < milli- < centi- < kilo-. The other choices are incorrect because they do not follow the correct increasing order of magnitude for the metric prefixes.

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.

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.