what is the product expressed to the correct number of significant figures regents

BIOL 1406

PreLab 1.6

When reporting a measurement, how many significant digits should I utilise?

When making measurements, you lot must study your results using the correct number of significant digits (besides called significant figures.)  The significance of a digit has to do with whether or not it represents a true measurement.   Any digit that can exist accurately measured or reasonably estimated with the particular measuring device you are using is considered significant. Information technology is easy to determine the number of significant digits when using a digital measuring device; simply assume that all digits shown on the display are pregnant.  For example, if you lot are weighing an object on an electronic balance and the display shows 93.14 thou, record all of the digits and presume that the balance can accurately estimate the weight to the nearest one-hundredth of a gram.  In this case there are 4 significant digits.

Balance reading with 4 meaning digits

When using an analog measuring device, the decision is a little more complicated.  In this instance, the start estimated digit should be the last meaning digit reported in the measured value.  For example if you are measuring temperature with a thermometer where the smallest calibration marks are ten degrees apart, and then the first estimated digit would be the nearest whole caste and that would be the last meaning digit reported in your value.  Such a thermometer could be used to report a temperature of 47 oC but not 47.0 oC or 47.00 oC.  On the other hand, if the smallest calibration marks on the thermometer are one degree autonomously, then the first estimated digit would be tenths of a degree and that should be the last pregnant digit reported in your value.  Such a thermometer could be used to study a temperature of 47.0 oC but not 47 oC or 47.00 oC. Look at the thermometer on the right, notice that the marks are in x degree increments. On this device, the most accurate measurement would exist plus or minus 1 degree. Therefore, the value should be read as 35 oC, not 35.0 oC.

Thermometer

Notice that on the meridian scale, we can approximate the distance more accurately, i.e. 3 significant digits, compared to the same altitude measured using the lesser scale, i.due east. 2 significant digits.

Your Plow
Look carefully at the picture below. Enter you answers in the space provided, so check and run into how you did.  Mouse over the links below to check your respond.
What is the length of the grey object? Don't forget the units!	Cheque your answer.
How many meaning digits does the measurement have?	Cheque your answer.
Mouse over for more information.

How practice I determine the number of pregnant digits in a reported measurement?

To determine the number of significant digits in a reported measurement, nosotros need to look at 2 cases:

A.    Numbers with Indicated Decimals

i. All non-zero digits (one-9) are counted as significant.

two. Only zeros that accept non-goose egg digits somewhere to the LEFT of them are considered pregnant � all other zeros are place holders

For example, in the value 0.0012010 thou, merely the final two zeros accept not-null digits to their left and are counted as significant.  The first 3 zeros are merely place holders and are non meaning digits.  Therefore, the full number of significant digits in this value is 5.

B.    Numbers without Indicated Decimals

1. All non-nothing digits (1-9) are counted as meaning.

two. Zeros that have not-zero digits somewhere to the RIGHT of them are considered meaning, but there is no way of knowing whether whatsoever other zeros are significant.

For example, in the value 100,500 thousand, the first 2 zeros are significant because there is a non-null digit to their right.  Nonetheless, we really don�t know if the iii^rd or 4^thursday zeros are meaning.  This ambivalence can exist avoided by writing the number with a decimal or by using scientific annotation.  When using scientific notation, all digits before the multiplication sign are considered significant.  For example, to write 100,500 1000 using scientific note:

• If the 3^rd and four^th zeros are non significant, you could write 100.5 x 10ⁱⁱⁱ g  (4 significant digits)

• If the 3^rd nil is significant but not the fourth, you could write 100.50 ten x³ g  (5 significant digits)

• If both the 3^rd and 4^th zeros are significant, you could write 100.500 ten tenⁱⁱⁱ g  (six significant digits)

Your Turn
You are measuring the migration distance of poly peptide bands in a gel using a ruler where the smallest calibration marks are i mm apart.  For each of the post-obit recorded measurements blazon in "yes" if information technology has the right number of significant digits and blazon in "no" if it does non.
23 mm	Hint	Cheque your answer.
23.0 mm	Hint	Check your answer.
2.iii cm	Hint	Check your respond.
2.333 cm	Hint	Check your respond.
2.34 cm	Hint	Bank check your answer.
23.64 mm	Hint	Check your answer.
0.0231 m	Hint	Check your respond.
Write downward the number of significant digits in each of the following recorded measurements.
23.0167 g	Hint	Check your answer.
0.0034 g	Hint	Check your answer.
45.0021 g	Hint	Check your answer.
104.50 thou	Hint	Check your answer.
0.0010 one thousand	Hint	Check your answer.
3.00 x 104 g	Hint	Bank check your answer.

---

Close this browser window to return to Blackboard and consummate the practice quiz and assessment quiz.

browntiquitim.blogspot.com

Source: https://accmultimedia.austincc.edu/biocr/1406/labm/ex1/prelab_1_6.htm

Share this post