# More Practice ```MORE QUARTERLY EXAM PRACTICE PROBLEMS
1. Complete each calculation below. Report answers in scientific notation with the correct number of
significant digits:
a. 0.00325g + 0.098g – 0.02164g =
b. 235kg x 33.25m &divide; 64sec2 =
2. There are 197 houses in my neighborhood. Each property has a lot width of 545 feet. I can trick-or-treat at
a rate of 5.16 x 109 &micro;m/hr. How many houses can I cover in 115 minutes? Use dimensional analysis to solve!
Show unit cancellation. (1 inch = 2.54cm.)
3. Nickel has a density of 8.9 g/cm3.
Find the volume of 500 mg of nickel.
4. Determine the half life of a radioactive isotope if a 2800ng sample of the isotope decays to 175ng in 32
minutes.
5. Write the equations for the following nuclear reactions:
154
62𝑆𝑚
- alpha decay
______________________________________________________
140
56𝐵𝑎
- beta decay
_______________________________________________________
244
94𝑃𝑢
- alpha decay with gamma radiation: __________________________________________
6. The atomic mass and relative abundance of the isotopes of lead are given in the chart below. Use the data to
calculate the average atomic mass of lead.
Isotope Atomic mass (amu)
204
Pb
Pb
207
Pb
208
Pb
206
203.97
205.97
206.98
207.98
Natural abundance
(atom %)
1.4
24.1
22.1
52.4
7. The element boron has two naturally occurring isotopes. 105𝐵 has an atomic mass of 10.00amu, and
an atomic mass of 11.01amu. The mass of boron on the periodic table is 10.81amu. Find the relative
abundance of each isotope.
11
5𝐵
has
8. Find the wavelength of a photon of light, in nm, if the energy is 3.33 x 10-19J.
9. Find the frequency of energy with a wavelength of 0.0045cm.
10. The data below was collected for two different sized screws, each made from the same type of metal. The
volumes of the screws were to be determined by water displacement. Use the data in the table below to
determine the final water level for the second screw.
Screw #
1
2
Mass
10.25 g
14.47 g
Initial Water Level
1.20 mL
5.00 mL
1a. 8.0 x 10-2g
b. 1.2 x 102 kg . m/ sec2
2. 59.5 houses
7. 19.80% 10B, 80.20% 11B
8. 597nm
Final Water Level
2.50 mL
??
3. 0.06cm3
4. 8.0 minutes
9. 6.7 x 1012 Hz
6. 207.22amu
10. 6.83mL
```