activity radioactivity

.e., polonium, radium, etc., which were more active than uranium. These substances, which have the property of spontaneous emission of radiation are called radioactive substances and the process of spontaneous emission of radiation is called Radioactivity. It was later..

The phenomenon of spontaneous disintegration of an unstable nucleus of naturally occurring isotope accompanied by emission of active radiations line a , b and g radiations is known as Natural Radioactivity. These radiations come from the breakup of the central core or nucl..

The table shows the weight of a radioactive substance, which decreases by 1 2 every year. Find the weight of the radioactive substance in the 3 rd year. Time Weight of radio active substance Initial 3200 g 1 st year 1600 g 2 nd year 800 g 3 rd year -- 4 th year 200 g =..

Determine the half life of a radioactive material if its activity falls to ..

You have learnt in the earlier chapters that flow of electrons constitutes an electric current and current can be generated from a battery or a generator. Scientists later discovered that there are many other ways of producing the stream of electrons. This knowledge has led to further developments ..

We know that the activity of a radioactive sample is directly proportional to the number of atoms present. ..

The important point is that it is now possible to produce any radioisotope. Most of those produced have short half-life periods. This is very important because the activity and hence the danger from radioactive emissions does not last very lo..

Positron Emission Tomography (PET) - PET is a sophisticated version of radio isotope scanning. The principle behind PET scanning is as follows. Short - lived radio isotopes such as 1 1 C, 1 3 N or 1 5 O are produced and incorporated into a solution (of glucose) that can be injected into the body. A..

Thus it is evident that t 1 / 2 of an element does not depend on the initial amount of radioactive element but depends on the value of l . The t 1 / 2 of a particular radioactive isotope is a characteristic constant of that isotope. Values of t 1 / 2 range from millions of years..

Water Pollution - Water constitutes nearly three-fourths of the Earth's surface and it composes a large proportion of all living plant and animal matter. Approximately 70% of human body is water. Man drinks about 2 liters of water daily and it is required in abundance for domestic use, agricultural..