Chem 1                   Worksheet #15         Text Reference:  Pgs 44-48, 50-52    Name ____________________________

 

Vocabulary:  standard scientific notation, exponent, significant figure, accuracy, precision

 

Summary:  The use of scientific notation is explored as well as determining the number of significant figures in measurements. 

 

1.      Express each of the following numbers in standard scientific notation.

a.       529

b.      240,000,000

c.       301,000,000,000,000,000

d.      78,444

e.       0.0202

f.        0.1550

g.       0.0000104

h.       0.000000000000000000129

 

2.      Express each of the following as an "ordinary" decimal number.

a.       7.24 x 10-9

b.      1.9444 x 10-6

c.       4.921 x 10-3

d.      1.4 x 101

e.       4.6 x 100

f.        3.954 x 103

g.       7.4434 x 105

h.       2.9 x 102

i.         1.03 x 109

 

3.   If  you are using a ruler to measure the length of a pencil, and the ruler has divisions in inches, which of the following measurements for the length of the pencil are reasonable (correct). You may choose any that are correct.

 

a) 3 in.___ b) 3.5 in.___ c) 3.48 in. ____ d) 3.4 in. ___ e) 4 in. ___ f) 3.49 in. ___ g) 3.51 in. ___

 

How many certain digits are there in the correct measurements? ______

How many uncertain digits are there in the correct measurements? ______

How many significant digits are there in the correct measurements? ______

 

4.    How many significant figures are there in each of the following measurements?

 

a. 1.498 grams            _____                          b. 248.3 seconds _____

c. 9.855 milliliters _____                        d. 76.414 kg _____

e.  8.0335 cm _____                          f.  0.05587 m _____

g. 1.40082 cm_____                                  h. 0.00058900 g _____

i.  0.00300900870 mm_____                  j. 4500 km _____

k. 350.000 cm             _____                          h. 3.50 x 103 cm _____

i.  1.604 x 10-4 m_____                       j.  0.040 x 107 g _____

k.  575 twinkies _____             l.  3 prom queens _____