discovery x-rays

. The radiation has a dual aspect behaving either as waves or as particles (waves when it interferes, diffracts and particles in a photocell). Einstein showed that a particle having a finite mass has been supposed to be associated with a definite amount of energy given by his mass-energy relationsh..

Atoms are made up of three fundamental particles: electrons, protons and neutrons. Discharge tube experiments by William Crookes and J.J. Thomson led to the discovery of electron. Goldstein's experiment with the discharge tube having a perforated cathode led to the discoveryh..

J.J.Thomson proposed the first simple and most primitive model in 1898, which considered an atom to be a sphere of uniform positive charge into which the negatively charged electrons were embedded. This model was like a plum pudding dotted with raisins and was thus called as 'plum pudding' model o..

Angiography - Angiography involves injecting a dye directly into the blood and then taking X-rays of the arteries. Angiography of the blood vessels of the heart is called Coronary angiography. X-rays when coupled with image intensifiers gives a more real image. During surgery, t..

In conventional X-rays an overlap of organs occurs and often difficult to interpret. These diagnostic difficulties have been eliminated by the use of an X-ray technique called computer Tomography (CT) scaning or computerised Axial Tomography (CAT) Scannin..

Moseley had done experiments on the characteristic X-rays and this led to the development of the concept of atomic numbe..

. In it, he pictured a sphere of positive charges mixed together with an equal number of electrons. For his theoretical and experimental investigations into the electron and the conduction of electricity by gases he was awarded the 1906 Noble prize in Physics. He and his student Rutherford were the..

Mutations are defined as heritable changes in structure number of genes or chromosomes. Mutations can be natural (spontaneous) or induced. Many natural mutations are recorded. But, stability of mutant expression needs a thorough testing over generations, as many mutants have tendency to revert to n..

Mutation Breeding - Mutations are defined as heritable changes in structure number of genes or chromosomes. Mutations can be natural (spontaneous) or induced. Many natural mutations are recorded. But, stability of mutant expression needs a thorough testing over generations, as many mutants have ten..

Genetic Code - The complex process by which the information in RNA is decoded into a polypeptide is one of the exciting discoveries the genetic code. With only four biochemical letters (A, G, C, U) a one letter code could not unambiguously encode 20 amino acids. A two letter code could en..