Chemistry First nine weeks review– Show all work or receive no credit
Define the following terms
chemical change
density
extensive property
intensive property
physical change
isotope
average atomic mass
molar mass
Conversion factor
Mixture
Compound
Solution
alloy
1. Explain how you can tell that a chemical change has occurred.
2. List 3 changes that are physical changes
3. Answer the following with the correct number of sig figs
a. 3.60 x 4.59
b. 4.70 x 10-14 / 1.9 x 10-12
c. 6.203 + 9.4
4. How many sig figs do each of the following numbers have?
a. 36040
b. 89000
c. 400.
d. 0.003
e. 0.3030
f. 0.0004500
5. If you have a sample of an unknown substance what types of experiments could you
conduct to see if it is a pure substance?
6. Give 3 examples of
a. Homogenous mixtures
b. Heterogenous mixtures
c. Compounds
d. elements
7. If you have a mole of Carbon, what does that mean to you?
8. Compare a mole of nitrogen to a mole of Calcium. What is different and what is the
same?
9. Explain how to calculate average atomic mass.
Isotope
Mass Number (grams)
Percent Abundance (%)
A
12.2
15
B
13.1
50
C
14.9
35
10. What is the average atomic mass of the element above?
11. An element has 4 stable isotopes. What is the average atomic mass and which element
is this?
Mass
204
206
207
208
% Abundance
1.4%
24.1%
22.1%
?
12. List 3 conversion factors that you have used outside of school
13. What are the molar masses of the following
a. Ca
b. N
c. PbNO3
d. Al(NO3)
e. If you had 4.67 grams of aluminum nitrate (listed in part d above), how many
moles would that be? How many atoms?
14. Explain how the kinetic molecular theory describes the motion of solids, liquids, and
gases.
15. Are all particles moving all the time or do some atoms stay still?
16. Do all atoms of the same element have the same mass? Explain.
Midterm Practice Questions
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1. The average atomic mass of an element is the average of the atomic masses of its
a. naturally occurring isotopes.
c. radioactive isotopes.
b. two most abundant isotopes.
d. artificial isotopes.
____
2. A prospector finds 39.39 g of pure gold (atomic mass 196.9665 amu). She has
a. 1.204  1023 atoms of Au.
c. 4.306  1023 atoms of Au.
23
b. 2.308  10 atoms of Au.
d. 6.022  1023 atoms of Au.
____
3. A sample of tin (atomic mass 118.71 amu) contains 3.01  1023 atoms. The mass of the sample is
a. 3.01 g.
c. 72.6 g.
b. 59.3 g.
d. 11 g.
____
4. Which of the following is an extensive property of matter?
a. melting point
c. volume
b. boiling point
d. Density
____
5. Which of the following is an intensive property of matter?
a. amount of energy
c. volume
b. density
d. mass
____
6. The relationship between the mass m of a material, its volume V, and its density D is
a. D = mV.
c. D = m/V.
b. D = V/m.
d. D = m + v.
____
7. 0.25 g is equivalent to
a. 250 kg.
b. 250 mg.
c. 0.025 mg.
d. 0.025 kg.
____
8. The number of significant figures in the measurement 2010 cm is
a. 1.
c. 3.
b. 2.
d. 4.
____
9. Which of the following lists atomic orbitals in the correct order they are filled according to the
Aufbau principle?
a. 1s 2s 2p 3s 4s 3p 3d 4p 5s
b. 1s 2s 2p 3s 3p 4s 3d 4p 5s
c. 1s 2s 2p 3s 3p 4s 4p 3d 4d
d. 1s 2s 2p 3s 3p 3d 4s 4p 5s
____ 10. The element with electron configuration 1s2 2s2 2p6 3s2 3p2 is
a. Mg (Z = 12).
c. S (Z = 16).
b. C (Z = 6).
d. Si (Z = 14).
____ 11. The electron notation for aluminum (atomic number 13) is
a. 1s2 2s2 2p3 3s2 3p3 3d1.
b. 1s2 2s2 2p6 3s2 2d1.
c. 1s2 2s2 2p6 3s2 3p1.
d. 1s2 2s2 2p9.
Chemistry Nine weeks Review Part 2
Define the following Terms
Nuclear reaction
Alpha particle
Beta particle
1. Explain alpha decay and give 1 example of a nuclear equation that shows alpha decay.
2. Compare and contrast fission and fusion. Where do these reactions occur? We use
fission for power but not fusion, even though fusion produces more power. Why don’t
we use fusion?
3. Describe the differences in charge and mass between alpha, beta, and gamma radiation.
4. Draw a picture of an alpha and a beta particle moving between 2 electrodes. One
electrode is positively charged and the other is negatively charged.
5. What was discovered in the cathode ray tube experiment? How were they discovered?
Who discovered them?
6. Which of Dalton’s postulates disagrees with modern atomic theory?
7. What were the conclusions that resulted from Rutherford’s gold foil experiment?
8. Draw and label a picture of the Bohr model.
9. Write an electron configuration that is wrong and explain why it’s wrong and which rule
it violates.
10. What is the energy of a wave with a frequency of 3.45 x 1014 Hz?
11. Do all light waves move at the same speed? Explain.
12. If a wave has a wavelength of 5.67 x 10-16 m what is the frequency?
13. What is the Energy of a 3.45 x 10-8 km wave?
14. How did Mendeleev arrange his periodic table?
15. How is our periodic table different today from Mendeleev’s.
16. Name 2 elements from the following groups
a. Halogens
b. Metalloids
c. Alkali metals
d. Alkaline earth metals
e. Noble gases
f. Transition metals
g. Lanthanides
h. Actinides
i. Non metals
Midterm Review Part 2
____
1. Balance the following equation:
____
a.
c.
b.
d.
____
2. Which of the following processes always decreases the number of protons by an even number?
a. fusion
c. alpha decay
b. beta decay
d. fission
____
3. Alpha particles are
a. electrons.
b. helium nuclei.
c. electromagnetic waves.
d. neutrons.
4. Beta particles are
a. electrons.
b. helium nuclei.
c. electromagnetic waves.
d. neutrons.
____
____
5. Which of the following is the symbol for an alpha particle?
a.
c.
b.
____
d.
6. Which of the following is the nuclear symbol for a beta particle?
a.
c.
b.
d.
____
7. A sample of tin (atomic mass 118.71 amu) contains 3.01  1023 atoms. The mass of the sample is
a. 3.01 g.
c. 72.6 g.
b. 59.3 g.
d. 11 g.
____
8. How many molecules are there in 5.0 g of methyl alcohol, CH3OH?
a. 9.4 1022
c. 3.6 1024
b. 3.0 1024
d. 3.8 1024
____
9. Which of the following lists atomic orbitals in the correct order they are filled according to the
Aufbau principle?
a. 1s 2s 2p 3s 4s 3p 3d 4p 5s
b. 1s 2s 2p 3s 3p 4s 3d 4p 5s
c. 1s 2s 2p 3s 3p 4s 4p 3d 4d
d. 1s 2s 2p 3s 3p 3d 4s 4p 5s
____ 10. The element with electron configuration 1s2 2s2 2p6 3s2 3p2 is
a. Mg (Z = 12).
c. S (Z = 16).
b. C (Z = 6).
d. Si (Z = 14).
____ 11. The electron notation for aluminum (atomic number 13) is
a. 1s2 2s2 2p3 3s2 3p3 3d1.
b. 1s2 2s2 2p6 3s2 2d1.
c. 1s2 2s2 2p6 3s2 3p1.
d. 1s2 2s2 2p9.