Fill in the Blanks for the following Table
|
Atom Name |
Number Neutrons |
Number Electrons |
Number Protons |
Nuclide Symbol w/charge (if
one) |
|
Oxygen -16 |
8 |
8 |
8 |
16O |
|
Oxygen- 18 |
10 |
10 |
8 |
18O-2 |
|
Iodine-127 |
74 |
54 |
53 |
127I- |
|
Carbon-14 |
8 |
6 |
6 |
14C |
|
Iron-56 |
30 |
24 |
26 |
56Fe+2 |
|
Iron-54 |
28 |
24 |
26 |
54Fe+2 |
|
Iorn-54 |
28 |
23 |
26 |
54Fe+3 |
|
Lead |
125 |
78 |
82 |
207Pb+4 |
|
Strontium-90 |
52 |
38 |
38 |
90Sr |
|
Barium- 140 |
84 |
54 |
56 |
140Ba+2 |
1. Calculate the atomic
weight of neon (to the correct number of significant figures) composed of three
naturally occurring isotopes with the following natural abundances and masses:
a. 90.51% neon-20 (mass = 19.992 amu)
b. 0.27% neon-21 (mass = 20.993 amu)
c. 9.22% neon-22 (mass = 21.991 amu)
2. Silicon has three naturally occurring isotopes. Silicon-28 is 92.2% abundant and has a mass of 27.979 amu, silicon-29 is 4.705% abundant and has a mass of 28.968 amu, and silicon-30 is 3.10% abundant and has a mass of 29.957 amu. What is the average mass of silicon?
3. An element has two naturally occurring isotopes. Isotope 1 has a mass of 106.905 amu and a relative abundance of 51.8%. Isotope 2 has a mass of 108.904 amu and a relative abundance of 48.2%. Find the atomic weight of this element and, by comparison to the periodic table, identify it.
4. A fictitious element has two naturally occurring isotopes and has an atomic weight of 29.5 amu.
a. If the natural abundance of isotope 1 is 33.7%, what is the natural abundance of isotope 2?
b. If the mass of isotope 2 is 30.0 amu, what is the mass of isotope 1?
5. Chlorine has two naturally occurring isotopes. Chlorine-35 has a mass of 34.969 amu and a relative abundance of of 75.53%. Use the atomic weight of chlorine to determine the mass of the second chlorine isotope.
Answers: 1)
20.18 amu 2) 29.0 amu
3) 107.9 amu = Ag 4)
a) 66.3%
b) 29 amu
5) 37.0 amu