When nuclei change spontaneously, emitting energy, they are
said to be radioactive.
Nuclear chemistry is the study of nuclear reactions and their
Nucleons are particles in the nucleus:
Types of Radioactive Decay
There are three types of radiation which we will consider:
-Radiation is the loss of (alpha particles) from the nucleus.
-Radiation is the loss of an electron from the nucleus.
These high-speed ele
Patterns of Nuclear Stability
The proton has high mass and high charge.
Therefore, the proton-proton repulsion is large.
In the nucleus the protons are very close to each other.
The cohesive forces in the nu
Nuclear transmutations are nuclear reactions resulting from
the collisions between nuclei or between a nucleus and a
Using Charged Particles
For example, nuclear transmutations can occur using highvelo
Transuranium elements follow uranium in the periodic table.
Rates of Radioactive Decay
Radioactive decay is a first-order process.
Each isotope has a characteristic half-life.
Half-lives are not affected by te
Calculations Based on Half-life
Radioactive decay is a first-order process:
Rate = kN
If the activity of a sample at time = t is Nt, and the activity at
time = 0 is N0, then:
The half-life of the sample is given by:
Photosynthesis has been studied using 14C:
614 CO2 + 6H2O
C6H12O6 + 6O2
The carbon dioxide is said to be 14C labeled.
The presence of 14C in the intermediates or products of
photosynthesis can be
Nuclear Binding Energies
The mass of a nucleus is less than the mass of its nucleons.
Mass defect is the difference in mass between the nucleus
and the masses of its nucleons.
Nuclear binding energy is the energy required to separat
Use fission as a power source.
Use a subcritical mass of 235U (238U is enriched with about 3%
Enriched 235UO2 pellets are encased in Zr or stainless steel
Control rods are composed of Cd or B, which a
Biological Effects of Radiation
Ionizing radiation involves ionization that occurs when
radiation removes an electron from an atom or molecule.
This is generally more harmful to biological systems than