4.10 CHAPTER 4. ATOMICNUCLEI
- There are three typesof radiation from radioactive decay: alpha (α), beta (β) and gamma (γ)
radiation. - During alpha decay, an alpha particle is released. An alpha particleconsists of two protons and
two neutrons bound together. Alpha radiation has low penetration power. - During beta decay, a beta particle is released. During beta decay, a neutron is convertedto a
proton, an electron anda neutrino. A beta particle is the electron that isreleased. Beta radiation
has greater penetration power than alpha radiation. - During gamma decay, electromagnetic energyis released as gamma rays. Gamma radiation has
the highest penetrationpower of the three radiation types. - There are many sources of radiation. Some sources are natural and others are man-made.
- Natural sources of radiation include cosmic and terrestrial radiation.
- Man-made sources ofradiation include televisions, smoke detectors, X-rays and radiation ther-
apy. - The half-life of an element is the time it takes for half the atoms of a radioisotope todecay into
other atoms. - Radiation can be verydamaging. Some of the negative impacts of radiation exposure include
damage to cells, geneticabnormalities and cancer. - Radiation can also havemanypositiveuses. These include use in the medical field (e.g. chemical
tracers), biochemistry and genetics, use in foodpreservation, the environment and in archaeol-
ogy. - Nuclear fission is the splitting of an atomic nucleus into smaller fission products. Nuclearfission
produces large amountsof energy, which can beused to produce nuclear power, and to make
nuclear weapons. - Nuclear fusion is the joining togetherof the nuclei of two atoms to form a heavier nucleus. In
stars, fusion reactions involve the joining of hydrogen atoms to form helium atoms. - Nucleosynthesis is the process of forming nuclei. This was very important in helping to form the
universe as we know it.
Chapter 4 End of Chapter Exercises
- Explain each of the following terms:
(a) electromagnetic force
(b) radioactive decay
(c) radiocarbon dating - The part of the atomthat undergoes radioactive decay is the...
(a) neutrons
(b) nucleus
(c) electrons
(d) entire atom - The radioisotope Po-212 undergoes alpha decay. Which of the following statements
is true?