1. Chapter 25: Nuclear Chemistry
Table of Contents
Chapter 25: Nuclear Chemistry
Fission, Fusion, Nuclear issues

2. So…half-lives are constant.
Nuclear Chemistry: Additional Concepts
1. Radiochemical Dating
Nuclear reaction rates remain constant regardless of changes which effect other chemical reactions
So…half-lives are constant.
Radiochemical dating: determining the age of an object by measuring the amount of a certain radioisotope remaining in that object.

3. Nuclear Chemistry: Additional Concepts
2. Nuclear fission
Heavy atoms (mass number > 60) tend to break into smaller atoms, increasing their stability.
Nuclear fission: splitting an atomic nuclei into 2 approximately equal parts.
Chain reaction
releases a large amount of energy.
Critical mass: The minimum amount of mass the starting material must have to sustain a chain reaction

4. Understand the pros and cons
Nuclear Chemistry: Additional Concepts
Nuclear reactors
Nuclear power plants use the process of nuclear fission to produce heat in nuclear reactors.
The heat is used to generate steam, which is then used to drive turbines that produce electricity.
7/8/10 –US Dept. of Energy announced $18.2 million for education in Nuclear Energy.
Understand the pros and cons

5. 2) What controls the temp? How? 1) What is the role of the fuel rods?
Nuclear Chemistry: Additional Concepts
Nuclear reactors
2) What controls the temp? How?
1) What is the role of the fuel rods?
FISSION → energy
Water slows neutrons
3) What keeps the process under control? How?
Control rods absorb neutrons

6. Cadmium and boron are used to keep the fission process under control.
Nuclear Chemistry: Additional Concepts
Nuclear reactors
Fissionable uranium(IV) oxide (UO2) is commonly used as fuel in nuclear reactors.
Cadmium and boron are used to keep the fission process under control.

7. 1 MWh = Energy for 650 houses, per hour.
1 ton of coal = 2.5 MWh

8. reactors able to produce more fuel than they use
Breeder reactor
reactors able to produce more fuel than they use

10. Yucca mountain – site for nuclear waste storage
Yucca mountain – site for nuclear waste storage

14. 2. Nuclear fission
Famous nuclear meltdowns
3 mile island (1979) – US
Chernobyl (1986) – Ukraine
several human errors & technical malfunctions
Fukushima (2011) – Japan
Following earthquake

15. Radiation energetic enough to ionize matter
Ionizing Radiation
Radiation energetic enough to ionize matter

16. Nuclear Power: 65,100 MW produced per water tower.
US uses 4 GW/yr, from 104 operating units. (100 GW possible).
Upside: most energy produced, produces weapons-grade Pu
Downside: requires U, & produces waste that will be radioactive for 4.5 billion years.

17. release very large amounts of energy
Nuclear Chemistry: Additional Concepts
3. Nuclear fusion
Nuclear fusion: nuclear reaction where small nuclei combine to form larger ones.
release very large amounts of energy
require extremely high temperatures. (also called thermonuclear reactions)

18. Solar Energy: Sun = the source of all energy on our planet.
The sun makes ~35,000 times the total energy used by man.
~1/3 of this energy is either absorbed by the atmosphere or reflected back into space.
40,000 watts of light per sq. in. of its surface, per second.

19. Additional Assessment Questions
Comprehension
What is the difference between nuclear fusion and nuclear fission?
Nuclear fusion is the combining of nuclei to form a single nucleus. Nuclear fission is the splitting of a nucleus into fragments.