Question

what do you mean by half life of a radioactive material?

Answer 1

The half-life of a radioactive substance is a characteristic constant. It measures the time it takes for a given amount of the substance to become reduced by half as a consequence of decay, and therefore, the emission of radiation.

Archeologists and geologists use half-life to date the age of organic objects in a process known as carbon dating. During beta decay, carbon 14 becomes nitrogen 14. At the time of death organisms stop producing carbon 14. Since half life is a constant, the ratio of carbon 14 to nitrogen 14 provides a measurement of the age of a sample.

The half-life of isotopes from some sample elements: oxygen 16 – infinite
uranium 238 – 4,460,000,000 years
uranium 235 – 713,000,000 years
carbon 14 – 5,730 years
cobalt 60 – 5.27 years
silver 94 - .42 seconds

Answer 2

half-life. ... For example, the half-life of a radioactive substance is the amount of time it takes for half of its atoms to decay, and the half-life of a drug is the amount of time it takes before half of the active elements are either eliminated or broken down by the body.