Notes and Study material for Exams
rawan239 Role Of Drdo In Various Fields (other than weapons) The Defence Research and Development Organisation (DRDO) is an agency of the Republic of India, charged with the military’s research and development, headquartered in New Delhi, India. It was formed in 1958 by the merger of the Technical Development Establishment and the Directorate of Technical Development … Read more
States of Matter Solids are formed when the attractive forces between individual Molecules are greater than the energy causing them to move apart. Individual molecules are locked in position near each other, and cannot move past one another. The atoms or molecules of solids remain in motion. However, that motion is limited to vibrational energy; … Read more
Acid An acid is a substance which forms H+ ions as the only positive ion in aqueous solution. Examples:- Hydrochloric acid dissolved in water forms H+ and Cl– ions HCl —> H+ + Cl– Sulphuric acid dissolved in water forms H+ and SO42- ions H2SO4 —>2H+ + SO42- Nitric acid forms H+ and NO3– ions when dissolved in water HNO3 —> H+ + NO3– … Read more
Corrosion is defined as an attack on a material as a result of chemical, frequently electrochemical reaction, with the surrounding medium. According to this definition, the term corrosion can be applied to all materials, including non-metals. But in practice, the word corrosion is mainly used in Conjunction with metallic materials. Why do metals corrode? Apart … Read more
Catalyst Catalyst, in chemistry, any substance that increases the rate of a reaction without itself being consumed. ENZYMES are naturally occurring catalysts responsible for many essential biochemical reactions. Most solid catalysts are metals or the oxides, sulfides, and halides of metallic Elements and of the semimetallic elements boron, aluminum, and silicon. Gaseous and liquid catalysts … Read more
Soap – Characteristics And Uses Soaps are excellent cleansing agents and have good biodegradability. A serious drawback which reduces their general use, is the tendency for the carboxylate ion to react with Ca+ and Mg+ ions in hard water. The result is a water insoluble salt which can be deposited on clothes and other surfaces. These … Read more
A molecule of high relative molecular mass, the structure of which essentially comprises the multiple repetition of units derived, actually or conceptually, from Molecules of low relative molecular mass is called a polymer. A polymer is a large molecule, or macromolecule, composed of many repeated subunits. Due to their broad range of properties,both synthetic and … Read more
Excretory System Introduction If you exercise on a hot day, you are likely to lose a lot of water in sweat. Then, for the next several hours, you may notice that you do not pass urine as often as normal and that your urine is darker than usual. Do you know why this happens? Your … Read more
Nervous System Of Human Being The nervous system is a complex collection of nerves and specialized cells known as neurons that transmit signals between different parts of the body. It is essentially the body’s electrical wiring. Structurally, the nervous system has two components: the central nervous system and the peripheral nervous system. According to the … Read more
Reproductive Systems The reproductive system in both males and females consists of structures that produce reproductive cells, or gametes, and secrete sex HORMONES. A gamete is a haploid cell that combines with another haploid gamete during fertilization. Sex hormones are chemical messengers that control sexual development and Reproduction. The male reproductive system consists of structures … Read more