"Half-life of radioactive element in the time interval during
which one half (50%) of the atom are disintegrated".
"Half life of a radioactive element in the time interval during which
(50%) of parents atoms are converted into daughter atoms or daughter element.
l x T1/2 =0.693
l = Decay constant
and T1/2 = Half-life.
substances have different half-lives.
1. Half-life of Krypton is 3.16 minutes.
2. Half-life of Radon 1s 3.82 days.
3. Half-life of Radium is 1600 years.
4. Half-life of Uranium is 4.47 x 109 years.
|Write four precautions to minimize radiation dangers (hazard)?|
radiation are very harmful for life i.e. for human being. Therefore, we
must have precautions against them:
(i) One should keep a safe distance away from the 'radiation emitting source'. the source emits radiation in all directions [it falls according to the relation 1/r2]. Where r is the distance of the source from the body.
(ii)The doctor, while giving the treatment to a patient by radiation should take the minimum possible time for radiation exposure.
(iii) The radiation from a nuclear reactor are shielded by thick concentrate wall.
(iv) In a laboratory, where radioactive materials are handled, the radioactive substance must be covered in a lead box with a lid made of lead.
|Write any four uses of radioactive isotopes?|
isotopes are widely used in the field of industry, agriculture and medicine.
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