# Chem 121 In-class assignment (10 pts) Names _____________________________

```Chem 121 In-class assignment (10 pts)
Names _____________________________
_______________________ _________________________ _____________________
1. Write the following numbers using scientific notation (exponential notation). Also,
state the number of significant figures there are for each value (Put your answer in the left
side of the number).
26000000000000000 m
1400 cm
0.0000060089 km
10 ft
0.1 mL
16,000,000 miles
2. Write the following exponential numbers in ‘standard’ form. Also, state the number of
significant figures there are for each value (Put your answer in the left side of the
number).
1 x 10 -13
1.123 x 10 7
2.7 x 10 -1
5.20098 x 10 -10
4.1 x 10 3
3. For each pair of numbers, circle which numbers are larger.
1 X 10 -13 and 2.2 X 10 -23
1 X 10 -13 and 7.2 X 10 -13
2.56 X 10 13 and 1.9 X 10 9
1 X 10 -11 and 1.1 X 10 -16
4. Using a ruler, measure the length and width of the front cover of your textbook.
How many significant figures are there in your measurements?
Did everyone’s measured values agree? If not, why not?
Now, calculate the area of the front cover. Is everyone’s answer the same? If not, why
not?
Should all the areas have the same number of significant figures? Why or why not?
```