non stoichiometric(metal excess defect) defects

Non-stoichiometric Defects - If an imperfection causes the ratio of cations to anions to become different from that indicated by the ideal chemical formula, the defect is called non-stoichiometric. There are three types: Metal excess ..

If an imperfection causes the ratio of cations to anions to become different from that indicated by the ideal chemical formula, the defect is called non-stoichiometric..

The defect, which arises due to the irregularity in the arrangement of atoms or ions are called point defects. Point defects are of three types: Stoichiometric defects Non-stoichiometric defects Impurity defects..

A bag contains 21 bulbs, out of which 10 are defective and 11 are non-defective. Express verbally the probability of picking a non-defective bulb. => 9 out of 21 or 11 out of 21 or 6 out of 21 or 13 out of 21..

A negative ion may be missing from its lattice site, leaving a hole, which is occupied by an electron thereby maintaining an electrical balance. The trapped electrons are called F-centers or color centers because they are responsible for imparting color to the crystal. Example: NaCl when heated in..

Extra cations occupying interstitial sites with electrons present in another interstitial site to maintain electrical neutrality can cause metal excess. This defect is similar to Frenkel defect and is formed in crystals having Frenkel defects. Exam..

In healthy individuals, the ECG remains reasonably constant, even though the heart rate changes with the demands of the body. The electrical activity of the heart shows changes under the following situations. a) Change in ionic environment of the heart b) A defect in the conduction system..

. It is characterised by the total absence of melanin in the skin, caused by the expression a homozygous recessive gene. Phenyl Ketonuria (PKU) is a metabolic disorder seen in growing children. In this condition an enzyme phenyl pyruvic hydroxylase necessary for amino acid metabolism, is not produc..

">Refractive Errors or Defects of Vision The abnormalities in the normal vision of the eye due to the change in focal length of the lens or due to the deformation of cornea are known as refractive errors or defects of vision. Myopia Myopia is an eye defect due to which..

1) The human body has elaborate mechanisms for protection against foreign bodies, germs and cancer cells. 2) Immunity is either innate or acquired. 3) Innate or non-specific immunity refers to a wide variety of body responses against a wide range of pathogens. 4) Previous exposure to an a..