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Assignment Preview |
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Title: Measurement and Significant Figures - Spring 2005 |
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Assignment Goals
Source Material
Student Instructions
Guiding Questions
Writing Prompt
Calibrations, Average Word
Count, and Answer Keys
In this assignment you
will:
- Explore the concept of significant figures in
measurements using several websites.
- Write an essay in which you describe
- how the number of
significant figures are determined in some example measurements someone
else has taken, and
- how to measure a volume in a buret to the correct number of significant figures.
Significant Figures Web Sites
The
source material for this assignment consists of several web pages that discuss
significant figures. None of these sites require special plug-ins. All that is
needed is a web browser, such as Netscape Navigator or Internet Explorer.
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Instructions for the Explorations
Follow
the links to the web sites found in the "Resources" section. Be sure
you read the Fable at the ChemTeam site! This
page addresses the question of why significant figures are important.
Once
you have read through the two websites and are able to answer the "Guiding
Questions," return to this site to continue with the writing assignment.
After
studying the resources, write your essay while considering the issues raised by
the following questions:
- Why is it important to be able to determine the
number of significant figures properly?
- Does the concept of significant figures deal with
precision or accuracy? Explain the meaning of both words briefly.
- What are the general rules for determining the number
of significant figures when making measurements in the lab using a
specific measuring device like a buret or a
ruler? How is the last digit of a measurement determined? Is it included
as a significant number?
- What is the volume of liquid in the buret shown in the photograph to the correct number of
significant figures? How was that value determined?
- Which statement is true? Every volume measured by the
same buret has the same number of significant
figures. Every volume measured by the same buret
has the same number of decimal places.
- How many significant figures are in each given
measurement in the Writing Prompt?
- Which zeros in the example numbers are
"place-holders?" Are "place-holding" numbers
considered to be significant or non-significant?
- Why is scientific notation useful for determining the
number of significant figures? Write Example (C) given in the Writing
Prompt in scientific notation to illustrate your point.
In a logical,
grammatically correct essay of the required length, divide your essay into
three paragraphs.
(1) Introduce significant
figures.
(2) Describe how to measure something to the correct number of significant
figures. Refer to the picture of the 50.0 mL buret in the Source Material. Include the correct volume of
liquid in the buret.
(3) Explain how to work with measurements determined by others. Consider the
following:
A. 0.00208 g
B. 250.0 cm
C. 1400 mL
Give the
correct number of significant figures present in each measurement, and describe
the rules you used to determine that number. Convert (C. 1400 mL) to scientific notation. Be sure to address the
items in the "guiding questions" section. Remember you are writing a
paragraph, not just answering a list of questions.
Note: Formatting from word processors is NOT preserved when you copy and
paste into the text box below. Refer to the HTML Tutor in the
"Source Material Resources" section to learn how to format your essay
with subscripts and superscripts, as well as line returns and paragraphs.
ALWAYS check your formatting by using the "Preview Text" button
below. This will show you exactly how your text will appear to reviewers.