radiations

The third mode of energy transfer between an object and its environment is via electromagnetic waves (visible light is a kind of electromagnetic wave). Energy transferred in this way is often called thermal radiation, to distinguish it from electromagnetic signals (as in, say, television ..

Background Radiation - In astronomy, the low temperature microwave radiation that arrives at the earth's surface from all directions of outer space is called background radiation. It is so named because it forms a background to all the radio sources that have been dete..

The first and only atomic bombs were used in war was in 1945 when Hiroshima and Nagasaki were devastated. Widespread destruction and damage were produced immediately by the blast. Some of the damage caused by the emitted radiation became evident within days, but some did not become evide..

The principle of adaptive radiation is based on two evolutionary mechanisms: Divergent evolutions Convergent evolutions Divergent evolution involves the homologous structures. A group of organisms modify a common homologous structure to perform different functions. An example is the..

Light has been regarded as waves to explain the phenomena of reflection, refraction, diffraction etc. However in 1905, Albert Einstein suggested that light has a dual character, which means, it can behave as a particle as well as a wave. It was observed that some of the experimental facts reg..

Dangers of Radiation - The first and only atomic bombs were used in war was in 1945 when Hiroshima and Nagasaki were devastated. Widespread destruction and damage were produced immediately by the blast. Some of the damage caused by the emitted radiation became evident within day..

In this, the cancerous parts of the body are exposed to ionising radiations like x-rays, which kill the cancerous cells. It gives good results in skin, lip, mouth and cervix cancers. Radiation therapy is used in 80% of cancer patients. The basic principle here is to bombard the..

In 1899, the study of radioactivity was taken up by Ernest Rutherford. He placed a little radium at the bottom of a small lead box and subjected the rays that emerged from it to the action of a very strong magnetic field at right angles to their direction. He found that the rays separated into thr..

Spontaneous Emission..

Discovery of Radioactivity and Nature of Radiations - In 1896, the phenomenon of radioactivity was accidentally discovered by French scientist Henri Becquerel. He was performing experiments with uranium compounds. He accidentally placed a crystal of potassium uranyl sulphate over photogra..