Chapter 17 · Radioactivity and Nuclear Chemistry
17.1Diagnosing Appendicitis
7 min · two checks
Predict
How can a nucleus be useful in medicine if chemistry is mostly about electrons?
The idea
- Separate nuclear change from chemical change.
- Name one medical use of radiation.
Chemical reactions rearrange electrons. Nuclear reactions change the nucleus: protons and neutrons. The energies are enormous compared with chemistry, and the process is almost indifferent to whether the atom is free, bonded, or inside a person. That indifference is exactly why a radioactive isotope of an element behaves chemically like the stable one and can be followed through the body.
Imaging and cancer treatment both use this. A tracer isotope concentrates where a certain chemistry happens, and the radiation reports the location. Other isotopes deliver a dose of radiation to a tumor. The rest of the chapter is the vocabulary of those emissions, how fast they fade, and the difference between a reactor, a bomb, and the Sun.
Keep these
- Nuclear reactions change the nucleus, not just electrons.
- Chemical conditions barely affect nuclear decay.
- Medicine uses both detection and deliberate irradiation.