• Medicine imaging and tumor treatments

Thyroid imaging using Tc-99

Uses of Nuclear Radiation

Food Irradiation• Food can be irradiated with gamma rays from 60Co or 137Cs.

• Irradiated milk has a shelf life of 3 months without refrigeration.

• USDA has approved irradiation of meats and eggs.

1000-10,000 kilorads

Isotope Half-Life Radiation Emitted

Carbon-14 5,730 years

Radon-222 3.8 days

Uranium-235 7.0 x 108 years

Uranium-238 4.46 x 109 years

• Radiocarbon Dating--The radioactivity of a sample can be used to determine how old it is.• Half-life: The time for half of the nuclei to decay.

Half-Life Graph

The times given in this table are the “half-life” values for the decay of U-238 into Pb-206.

Transuranium Elements: Beyond #92