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The first scientist to show that atoms emit any negative particles was
- A. J. J. Thomson
- B. Lord Kelvin
- C. Ernest Rutherford
- D. William Thomson
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.
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The melting point of indium is 2°C. At 323°F, what is the physical state of indium?
- A. Solid.
- B. Liquid.
- C. Gas.
- D. Not enough information.
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.
Order the four metric prefixes from smallest to largest.
- A. nano- < milli- < centi- < kilo-
- B. milli- < nano- < centi- < kilo-
- C. kilo- < centi- < nano- < milli-
- D. kilo- < centi- < milli- < nano-
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.
Which of the following is an example of a quantitative observation?
- A. The piece of metal is longer than the piece of wood.
- B. Solution 1 is much darker than solution
- C. The liquid in beaker A is blue.
- D. The temperature of the liquid is 60°C.
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.
A 0 mL sample of glycerol has a mass of 2 grams. What is the density of glycerol in ounces/quart? (00 ounce = 4 grams, and 00 liter = 06 quarts)
- A. 41.9 oz/qt
- B. 4.19 oz/qt
- C. 837 oz/qt
- D. 47.0 oz/qt
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.
Generally, observed behavior that can be formulated into a statement, sometimesmathematical in nature, is called a(n)
- A. observation
- B. measuremen t
- C. theory
- D. natural law
Correct Answer: A
Rationale: The correct answer is A: observation. Observations are specific instances of behavior that can be described and formulated into statements, including mathematical ones. Measurements (choice B) involve quantifying observations. Theories (choice C) are broader explanations based on observations. Natural laws (choice D) are general principles derived from consistent observations. In this context, the term "observed behavior" specifically points to the act of witnessing and formulating statements about behavior, making choice A the most suitable option.