- Name the three kinds of strength used to characterize materials AND give an example of a material that are strong in each of these modes.
- What kinds of bonding occurs in each of the three materials you listed in question #1?
- Explain how atoms can be arranged in such a way to create a permanent magnet.
- Identify 10 objects in your home that use semiconductors. What other kinds of materials with special electrical properties are found in all of these 10 objects?
- Research the status of magnetically levitated trains like the one now operating in China. How does it operate? How fast might it go?
- How does a nuclear reactor work?
- What types of researchers and scientists use carbon-14 radiometric dating? What type of researcher would use the other isotopes such as uranium-238?
- Use the periodic table to identify the element, its atomic number, mass number and electrical charge of the following:
| # Protons |
# Neutrons |
# Electrons |
Element Symbol |
Atomic Number |
Mass |
Electrical Charge |
| 1 |
0 |
1 |
|
|
|
|
| 8 |
8 |
8 |
|
|
|
|
| 17 |
18 |
18 |
|
|
|
|
| 36 |
50 |
36 |
|
|
|
|
- Potassium-40 decays into argon-40 with a half-life of 1.2 billion years. A particular mineral grain is known to have had a million potassium atoms in its crystal structure when it formed. When the grain was ground up, scientists discovered 750,000 atoms of argon-40. When did the grain form? (Hint: Use Figure 12-10 on page 272 to obtain a qualitative estimate).
- What are the half-lives of the following common isotopes:
- Carbon-14:
- Uranium-238:
- Uranium-235:
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