Unit 2 Name ______# ______
Section 1: Atomic Theory
1. Explain each of the laws in your own words.
a. Law of conservation of mass
b. Law of definite proportions
c. Law of multiple proportions
2. What was the significance of each of the following experiments?
a. Thomson’s cathode ray tube experiments
b. Rutherford’s gold foil experiment
3. Draw and describe the atom model of each of the following scientists.
a. Dalton
b. Thomson
c. Rutherford
d. Bohr
Section 2: Subatomic Particles of Neutral Atoms
NuclearSymbol / Isotope
Name / Atomic #
(Z) / Mass # (A) / Protons / Neutrons / Electrons
17 O
8
Arsenic - 75
Bismuth - 209
24 Mg
12
bromine - 80 / 35
50 V
23
31 / 70
119 / 50
3 / 4 / 3
7 / 7
Potassium - 40 / 19
31 / 15
93 / 237
73 / 39 / 34
Iron-58
201 Hg
80
243 / 95
41 / 53
Seaborgium-263
Darmstadtium-281
222 / 86
39 / 50
Berkelium-247
Section 3: Subatomic Particles in Ions
1. For each of the positive ions listed in column 1, use the periodic table to find in column 2 the total number of electrons that ion contains. The same answer may be used more than once.
____ 1. Al+3 A. 2
____ 2. Fe+3 B. 10
____ 3. Mg+2 C. 21
____ 4. Sn+2 D. 23
____ 5. Co+2 E. 24
____ 6. Co+3 F. 25
____ 7. Li+1 G. 36
____ 8. Cr+3 H. 48
____ 9. Rb+1 I. 76
____ 10. Pt+2 J. 81
2. For each of the following ions, indicate the total number of protons and electrons in the ion.
Ion / Number of Protons / Number of ElectronsCo+2
Co+3
Cl-1
K+1
S-2
Sr+2
Al+3
P-3
3. Write the chemical symbol for the ion with 12 protons and 10 electrons.
4. Write the chemical symbol for the ion with 74 protons and 68 electrons.
5. Write the chemical symbol for the ion with 95 protons and 89 electrons.
6. Write the chemical symbol for the ion with 33 protons and 36 electrons.
7. Write the chemical symbol for the ion with 29 protons and 27 electrons.
8. How many protons, neutrons, and electrons are present in the 59Ni+2 ion?
28
9. How many protons, neutrons, and electrons are present in the 91Zr+4 ion?
40
10. How many protons, neutrons, and electrons are present in the 140Ce+3 ion?
58
11. How many protons, neutrons, and electrons are present in the 79Se-2 ion?
34
12. How many protons, neutrons, and electrons are present in the 13C-4 ion?
6
13. Write the complete chemical symbol for the ion with 84 protons, 125 neutrons, and 80 electrons.
14. Write the complete chemical symbol for the ion with 27 protons, 32 neutrons, and 25 electrons.
15. Write the complete chemical symbol for the ion with 73 protons, 108 neutrons, and 68 electrons.
16. Write the complete chemical symbol for the ion with 31 protons, 39 neutrons, and 28 electrons.
Section 4: Average Atomic Mass
Calculate the average atomic masses. Round all answers to two decimal places.
1. Calculate the average atomic mass of magnesium using the following data for three magnesium isotopes.
Isotope mass (u) relative abundance
Mg-24 23.985 0.7870
Mg-25 24.986 0.1013
Mg-26 25.983 0.1117
2. Calculate the average atomic mass of iridium using the following data for two iridium isotopes.
Isotope mass (u) relative abundance
Ir-191 191.0 0.3758
Ir-193 193.0 0.6242
3. Nitrogen has two naturally-occuring isotopes, nitrogen-14 and nitrogen-15. The atomic mass of nitrogen-14 is 14.0031 amu and it accounts for 99.63% of naturally-occuring nitrogen. The second isotope, nitrogen-15, has a mass of 15.0001 amu and is 0.37% of nitrogen. Calculate the atomic mass of nitrogen from these data.
Section 5: Average Atomic Mass
Calculate the average atomic masses. Round all answers to two decimal places.
1. Rubidium has two common isotopes, 85Rb and 87Rb. If the abundance of 85Rb is 72.2% and the abundance of 87Rb is 27.8%, what is the average atomic mass of rubidium?
2. Uranium has three common isotopes. If the abundance of 234U is 0.01%, the abundance of 235U is 0.71%, and the abundance of 238U is 99.28%, what is the average atomic mass of uranium?
3. Titanium has five common isotopes: 46Ti (8.0%), 47Ti (7.8%), 48Ti (73.4%), 49Ti (5.5%), 50Ti (5.3%). What is the average atomic mass of titanium?
4. Calculate the atomic mass of the unknown element. Then identify the element.
Isotope Mass (amu) / Percent abundance185X / 184.953 / 37.40
187X / 186.956 / 62.60
5. Calculate the atomic mass of the unknown element. Then identify the element.
Isotope Mass (amu) / Percent abundance113X / 112.904 / 4.30
115X / 114.904 / 95.70
Section 6: Periodic Table
Periodic Table 1
Color the following categories:Key
Metals
Nonmetals
Metalloids
/
Periodic Table 2
Color the following categories:Key
Alkali Metals
Alkaline Earth Metals
Halogens
Noble Gases
/
Periodic Table 3
Color the following categories:Key
Transition Elements
Representative Elements
Lanthanides
Actinides
/
Periodic Table 4
Give each period a separateColor.
/
Periodic Table 5
Indicate the # of valence
electrons in groups 1,2
and in groups 13-18 at the
top of each group’s column.
/
Periodic Table 6
Indicate the seven diatomic elements by writing in their symbols in the appropriate boxes. Color is the squares for the elements that can be liquid in their natural state
/