Download Name Test Review Chemistry Unit 2: The Atom 1. Fill in the blank

Name __________________________________
Test Review
Chemistry Unit 2: The Atom
1. Fill in the blank with the name of the historical person associated with the reference. Some names will
be used more than once.
James Chadwick
John Dalton
Democritos
Eugene Goldstein
Antoine Lavoisier
Robert Millikan
Ernst Rutherford
JJ Thomson
Used the famous “gold foil” experiment. _________________________________
Discovered the proton _____________________________
Discovered the charged nucleus (small) is the center with 99.9% of the atom as empty space where the
electrons reside. _____________________________
Used an “oil drop” experiment to discover the charge and mass of an electron. __________________
Proposed the “Plum Pudding” model of the atom. ___________________________
Used the word “atomos” to describe matter. __________________________
Called the “Father of Modern Chemistry”. _________________________
Discovered the neutron. _______________________________
Created the first atomic theory based on experimental evidence. ___________________________
Discovered the electron. __________________________
Discovered the nucleus. ___________________________
Discovered the Law of Conservation of Mass. __________________________
Proposed a model of the atom as a hard, indivisible sphere. ________________________
Conducted experiments with cathode rays. ____________________________
Know the 5 points of Dalton’s atomic theory and how two of those points have been changed!
2. Fill in the following chart for the isotopes:
Isotope/Ion
Name
Symbol
Atomic
Number
(Z)
Mass
Number
(A)
Number
of
protons
Number
of
neutrons
Number
of
electrons
25
30
21
155
62
18
10
Antimony – 121
8
3. The most common isotopes of chromium are listed below. What is the average atomic mass of
chromium?
Isotope
Chromium – 50
Chromium – 52
Chromium – 53
Chromium – 54
Mass (amu)
49.9460
51.9405
52.9406
54.0022
Percent Abundance
4.55%
81.75%
9.81%
3.89%
85
87
85
4. Element X is a soft, silvery-white metal that has two common isotopes, X and X. If the abundance of X is
87
72.2% and the abundance of X is 27.8%, what is the average atomic mass of X? What is element X?
5. Silicon has three naturally occurring isotopes. What is the average atomic mass of silicon?
Isotope Name
Silicon-28
Silicon-29
Silicon-30
Isotope Mass (amu)
27.98
28.98
29.97
Relative Abundance (%)
92.21
4.70
3.09
6. How many atoms is 0.00556 moles of barium?
7. What is the mass of 0.44 moles of carbon?
8. How many atoms does 43.25 g of iron contain?
9. If a student weighs out 2.01 g of silicon, how many moles is that?
10. How many moles are there in 2.4010 x 1025 particles of gold?
11. What is the mass of a block of aluminum that has a volume of 22.4 cm3? (Density of Al = 2.70 g/cm3)
12. If a metal cylinder of copper (density = 8.9 g/cm3) has a mass of 45.4 grams, what is the volume of
the cylinder? What is the cylinder’s diameter if it is 1.2 cm in height?
13. Convert 2950 micrograms to kilograms.
14. Change 0.00014 hectoliters to nanoliters.
15. Write the symbols for an alpha particle, beta particle, and gamma ray.
16. When a nuclei undergoes alpha decay, how does the mass number change?
17. During beta decay, describe what happens to the atomic number of the element.
18. What is the most penetrating form of radioactive particles? What can stop this form of radioactivity?
19. Write the equations for the reaction when the following undergo alpha decay:
a. 235U
b. 241Am
c. 212At
d. seaborgium-263 (Sg)
92
95
85
20. Write the equations for the reactions when the following undergo beta decay:
a. 66Cu
b. 84Br
c. oxygen-18
d.
29
35
244
Cm
96
21. Write the equation showing the following isotopes undergoing gamma decay:
a. Radium-218 (Ra)
b. Uranium-239 (U)
22. If the half-life for the radioactive decay of zirconium-84 is 26 minutes and I start with a 175 gram
sample, how much will be left over after 104 minutes?
23. Mercury -197 is used for kidney scans and has a half-life of 3 days. If the amount of mercury-197
needed for a study is 1.0 gram and the time allowed for shipment is 15 days, how much mercury-197 will
need to be ordered?
24. How much strontium-90 will remain after 4 half-lives if the initial amount is 4.0 g?
25. Iodine-131 is used to destroy thyroid tissue in the treatment of an overactive thyroid. The half-life of
iodine-131 is 8 days. If a hospital receives a shipment of 550. g of iodine-131, how much I-131 would
remain after 60 days?