Warning: foreach() argument must be of type array|object, bool given in /var/www/html/web/app/themes/studypress-core-theme/template-parts/header/mobile-offcanvas.php on line 20

Nuclear fusion is a process whereby the nuclei of atoms are jouned, or "tused," and in which energy is released. One of the by-products of fusion is helium \(-4\) gas. A recent fusion experiment was conducted using "heavy" water contained in a sealed flask. The flask was, in turn, contained in an air- filled chamber designed to eliminate extraneous vibration. After the experiment, a measurable amount of helium-4 gas was found in the air of the chamber. The experimenters cited this evidence in support of their conclusion that fusion had been achieved. Which one of the following, if true, would cast doubt on the experimenters' conclusion? (A) Helium-4 was not the only gas found in the experiment chamber. (B) When fusion is achieved, it normally produces several by-products, including tritium and gamma rays. (C) The amount of helium-4 found in the chamber's air did not exceed the amount of helium-4 that is found in ordinary air. (D) Helium-4 gas rapidly breaks down, forming ordinary helium gas after a few hours. (E) Nuclear fusion reactions are characterized by the release of large amounts of heat.

Short Answer

Expert verified
Option (C) casts doubt on the experimenters' conclusion.

Step by step solution

01

Identify the experiment's goal

The goal of the experiment was to achieve nuclear fusion, evidenced by the presence of helium-4 gas as a by-product in the air of the chamber that would not normally exist unless fusion occurred.
02

Determine what finding helium-4 indicates

Finding helium-4 gas in the chamber is used by the experimenters to support their claim that fusion occurred during the experiment.
03

Evaluate each option for its potential to cast doubt

Evaluate the given options to see which one suggests that the presence of helium-4 gas might not be due to nuclear fusion.
04

Analyze Option (C)

Option (C) suggests that the amount of helium-4 found did not exceed the typical amount present in ordinary air. This implies that the helium-4 detected might not be unique to the experiment and thus, not necessarily evidence of fusion.
05

Conclusion on casting doubt

Option (C) effectively casts doubt on the claim that fusion was achieved, by suggesting that the presence of helium-4 may not have originated from the experiment due to its typical presence in ordinary air.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Nuclear Fusion
Nuclear fusion is a fascinating process whereby two atomic nuclei combine to form a heavier nucleus, releasing a massive amount of energy. This phenomenon primarily occurs in the cores of stars, where enormous pressure and temperature conditions enable fusion. On Earth, achieving controlled nuclear fusion could offer a nearly limitless and clean energy source, as it uses isotopes of hydrogen such as deuterium and tritium to generate energy.
The fusion process releases energy because the mass of the resulting atom is slightly less than the sum of the original nuclei. This lost mass is converted into energy according to Einstein's famous equation, ([E=mc^2](https://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence)), illustrating the efficient energy potential of fusion. Understanding this process aids in developing new energy technologies, potentially revolutionizing how humanity produces and consumes energy. Exploring the depths of nuclear processes not only strengthens scientific knowledge but also enhances our capability to harness them for practical uses.
Scientific Experimentation
Scientific experimentation serves as the backbone for testing hypotheses, understanding phenomena, and establishing scientific facts. It involves a systematic process: framing research questions, designing experiments, collecting data, and analyzing results. Each step is critical. In a nuclear fusion experiment, accurate observations lead to evidence-based conclusions.
Experiments are meticulously planned to control variables, eliminate biases, and achieve reliable results. In this context, factors such as ensuring no contamination of helium-4 from external sources and maintaining stable conditions in the experimentation chamber are paramount. Furthermore, successful experimentation requires careful documentation and repeatability, ensuring that findings are reliable and verifiable by independent researchers. An experiment's integrity relies on its design and execution, profoundly affecting the credibility of its conclusions.
Critical Thinking
Critical thinking plays a vital role in interpreting experimental results. It demands more than a surface-level acceptance of outcomes, requiring deep analysis and questioning of findings. By engaging critical thinking, scientists and students alike can challenge assumptions and evaluate whether the presented evidence truly supports the conclusions drawn.
For example, in the nuclear fusion experiment, individuals must scrutinize whether the detected helium-4 gas genuinely indicates fusion or if alternative explanations exist. Critical thinkers look beyond the obvious, asking essential questions like: Does the amount of helium-4 align with background atmospheric levels? Are there other potential sources for the helium-4? Critical thinking encourages diverse perspectives, leading to more nuanced understanding and more robust scientific inquiry. Hence, fostering such skills empowers learners to approach problems holistically and with open-minded skepticism.
Evidence Evaluation
Evaluating evidence involves assessing the strength and relevance of data to support a scientific claim. In scientific inquiries, such as nuclear fusion experiments, it is crucial to determine whether evidence like the presence of helium-4 truly substantiates the experimenters' claims. This evaluation process requires an objective analysis of the data quality and context.
Key steps in evidence evaluation include: - Ensuring data accuracy - Comparing experimental results with expected benchmarks - Considering potential sources of error or bias - Evaluating the representativeness of the data gathered Moreover, real-world applications demand that the given evidence must not only be consistent but also sufficient to confirm the hypothesis. For instance, if the helium-4 levels do not surpass typical atmospheric amounts, this could weaken the claim that nuclear fusion occurred. Thus, rigorous evidence evaluation is essential for advancing scientific knowledge and validating experimental findings.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Dried grass clippings mixed into garden soil gradually decompose, providing nutrients for beneficial soil bacteria. This results in better-than-average plant growth. Yet mixing fresh grass clippings into garden soil usually causes poorer-than-average plant growth. Which one of the following, if true, most helps to explain the difference in plant growth described above? (A) The number of beneficial soil bacteria increases whenever any kind of plant material is mixed into garden soil. (B) Nutrients released by dried grass clippings are immediately available to beneficial soil bacteria. (C) Some dried grass clippings retain nutrients originally derived from commercial lawn fertilizers, and thus provide additional enrichment to the soil. (D) Fresh grass clippings mixed into soil decompose rapidly, generating high levels of heat that kill beneficial soil bacteria. (E) When a mix of fresh and dried grass clippings is mixed into garden soil, plant growth often decreases.

Measurements of the extent of amino-acid decomposition in fragments of eggshell found at archaeological sites in such places as southern Africa can be used to obtain accurate dates for sites up to 200,000 years old. Because the decomposition is slower in cool climates, the technique can be used to obtain accurate dates for sites almost a million years old in cooler regions. The information above provides the most support for which one of the following conclusions? (A) The oldest archaeological sites are not in southern Africa, but rather in cooler regions of the world. (B) The amino-acid decomposition that enables eggshells to be used in dating does not take place in other organic matter found at ancient archacological sites. (C) If the site being dated has been subject to large unsuspected climatic fluctuations during the time the eggshell has been at the site, application of the technique is less likely to yield accurate results. (D) After 200,000 years in a cool climate, less than one-fifth of the amino acids in a fragment of eggshell that would provide material for dating with the technique will have decomposed and will thus no longer be suitable for examination by the technique. (E) Fragments of eggshell are more likely to be found at ancient archacological sites in warm regions of the world than at such sites in cooler regions.

"If the forest continues to disappear at its present pace, the koala will approach extinction," said the biologist. "So all that is needed to save the koala is to stop deforestation," said the politician. Which one of the following statements is consistent with the biologist's claim but not with the politician's claim? (A) Deforestation continues and the koala becomes extinct. (B) Deforestation is stopped and the koala becomes extinct. (C) Reforestation begins and the koala survives. (D) Deforestation is slowed and the koala survives. (E) Deforestation is slowed and the koala approaches extinction.

Alice: Quotas on automobile imports to the United States should be eliminated. Then domestic producers would have to compete directly with Japanese manufacturers and would be forced to produce higher-quality cars. Such competition would be good for consumers. David: You fail to realize, Alice, that quotas on automobile imports are pervasive worldwide. Since Germany, Britain, and France have quotas, so should the United States. Which one of the following most accurately characterizes David's response to Alice's statement? (A) David falsely accuses Alice of contradicting herself. (B) David unfairly directs his argument against Alice personally. (C) David uncovers a hidden assumption underlying Alice's position. (D) David takes a position that is similar to the one Alice has taken. (E) David fails to address the reasons Alice cites in favor of her conclusion.

A gas tax of one cent per gallon would raise one billion dollars per year at current consumption rates. Since a tax of fifty cents per gallon would therefore raise fifty billion dollars per year, it seems a perfect way to deal with the federal budget deficit. This tax would have the additional advantage that the resulting drop in the demand for gasoline would be ecologically sound and would keep our country from being too dependent on foreign oil producers. Which one of the following most clearly identifies an error in the author's reasoning? (A) The author cites irrelevant data. (B) The author relies on incorrect current consumption figures. (C) The author makes incompatible assumptions. (D) The author mistakes an effect for a cause. (E) The author appeals to conscience rather than reason.

See all solutions

Recommended explanations on English Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free