A student reads in a newspaper that the soil in his area contains high levels of arsenic. Based on this information, he believes
that his fellow high school classmates have this metal present in their bodies. To test his hypothesis, he conducts an investigation of the soil in his schoolyard to see if it is contaminated with arsenic. He tests seven different areas around the school and finds high levels of arsenic in each. He concludes that the students at the school must have high levels of arsenic in their systems as well. Which of these is the best evaluation of his conclusion? A. His conclusion is valid because he tested enough areas of soil to validate his hypothesis.
B. His conclusion is flawed because he did not test the soil at the homes where the students lived.
C. His conclusion is valid because arsenic is a toxic metal and is easily absorbed by the human body.
D. His conclusion is flawed because he did not test the students to see if their bodies contained metal arsenic.
Answer: D. His conclusion is flawed because he did not test the students to see if their bodies contained metal arsenic.
Explanation:
According to the given situation, student has tested seven different areas around the school to determine the presence of arsenic in the soil and also found the presence of arsenic in the school system. But has not studied the presence of arsenic in the students to support the fact that the school students are also affected by arsenic. So, conclusions based on the presence of arsenic in the soil and the system is inconclusive for the present study.
The phrase that best describe the word "energy" is letter "C. the ability to do work". The unit most commonly used to express energy is Joules (J) which is also derived from the equation of work which is the product of force and the distance that a body moves parallel to the force applied.
