what is pm in chemistry

George Goble was distinguished for his world-record time igniting a barbecue grill - three seconds, using charcoal and liquid oxygen. Frustrated by the 40 minutes it normally took to get the grill going, Goble, a computer engineer, and some of his friends experimented with alternative for..

. Objections to Kekule's structure (i) Benzene does not respond to unsaturation tests. (ii) It resists the addition reactions and undergoes preferably substitution reactions. (iii) Kekule's structure accounts for the formation of four (1,2-, 1,3-; 1,4- and 1,6-) disubstituted products but only thre..

) the solution is boiled (2) an electrolyte is added (3) a little lyophilic colloid is added (4) oppositely charged colloid is added 54. In NaCl unit cell, if Na + ions are present at the corners of the cube then Cl~ ions are present at (1) face centres (2) body centre (3) both edge centre and body..

Traditionally, chemistry has been divided into three branches - organic, inorganic and physical chemistry. Organic chemistry is the study of compounds of carbon. Inorganic chemistry is the study of compounds of all other elements and a few compounds of ..

The division into orgnic and inorganic chemistry is a fundamental division in chemistry. Carbon compounds have necessitated a seperate branch because of the innumerable number and typical properties of carbon compounds. The number of carbon compounds of all the other elem..

We begin with some inportant definations in surface chemistry..

Chemistry is intimately connected with the development of technology. The manufacture of metals, steel, glass, plastics, paper, cement, textiles, dyes, drugs and so on are directly associated with chemistry. The wonder drugs penicillin and streptomycin, anaesthetics, disi..

This unit deals with some important features of surface chemistry such as adsorption, catalysis, colloids, emulsions etc. The term surface or interface as interpreted in surface chemistry refers to a region where two phases meet. Most of the physical and chemical processe..

A recent attempt for the prevention of environmental pollution is the introduction of Green chemistry. This new branch of chemistry deals with processes and products that reduce or eliminate the use and generation of hazardous substances. Concentration on this line of act..

There are several aspects to the formal study of any language. (i) One begins by learning the letters of the alphabets of that language (ii) Then one learns to spell words by arranging these letters. (iii) The words are then set according to the rules of grammar so that they form mean..