Scientific Terms Explained - N to Z

This is part 2 of the glossary of scientific terms. You can refer to the part 1 of scientific terms and their meanings here.

Scientific Terms Explained - N to Z

Nitrogen Fixation – Nitrogen has the property of reacting under special conditions to form a number of useful products. Owing to this property the free atmospheric nitrogen is converted into so many nitrogenous compounds.

Neutralization – Addition of acid to alkali or vice-versa, so that the solution is neutralized, the properties of the compounds disappear.

Neutron Bomb – Developed by the United States, the bomb causes negligible damage to buildings and other installations, but kills people instantly through radiation.

Nuclear Fission – It is the process of breaking apart of the nucleus of an atom.

Nuclear Fuel – It is a substance which undergoes nuclear fission in a nuclear reactor.

Osmosis – In the process of a solution being separated from its pure solvent by a semi-porous membrane, the molecules of the solvent begin to travel across the membrane and reach the solution to dilute it. The process goes on till concentration is equal on both sides of the membrane. This phenomenon is known as Osmosis.

Outer space – The part of the universe which lies beyond the earth's atmosphere where the density of matter is very low.

Oxidation – It is a process of addition of oxygen.

Photosynthesis – Chemical union of two or more molecules of the same compound to form larger molecules. The process results in the formation of a new compound of the same empirical formula but greater molecular weight.

Potential energy – It is the energy possessed by the body by virtue of its position or shape.

Protoplasm – It is the living matter present in the cells of animal and vegetable life.

Psychedelic drugs – These are the drugs which produce a mental state of great calm.

Radiation – The process of transmission of heat in straight lines without heating the intervening medium.

Radio activity – It is a characteristic of substances like uranium, thorium, radium and actinium to emit radiation which can penetrate opaque substances, affects a photographic plate in the dark and ionize gases etc.

Refraction – When a ray of light enters from a rare medium to a denser medium, it is bent or refracted towards the normal. Mirage is formed by refraction.

Rocket – A type of vehicle driven by the engine which does not depend upon air as medium. It is therefore capable of working in outer space.

Relativity theory – Theory associated with Albert Einstein based on the principle that all motions are relative and that time and space are mutually inseparable.

'RRR' Bomb – The U.S. Government has begun secret exploratory research on a new nuclear 'fast bomb' known as RRR bomb (Reduced Residual Radiation bomb) for the military that would produce increased heat and blast but reduced radioactive fall out.

Specific gravity – Relative weight of any kind of matter expressed by the ratio of given volume to the same volume of water (for liquid or solid matter) and of air (for gas).

Spectrum – When a narrow beam of light passes through a prism, it disperses into seven colors. The colored image is known as spectrum.

Sterilization – (a) Removing the power of procreation by means of operation, (b) disinfecting instruments and other materials before performing a surgical operation.

Telex – Means Teleprinter Exchange. It enables subscribes to have their own teleprinter communication direct with any other subscriber having the same facility.

T.N.T. – Trinitrotoluene, highly explosive substance. It is manufactured by the action of concentrated nitric acid on toluene.

Torricellian Vacuum – The vacant space above the level of mercury in the barometer in known as Torricellian Vacuum. It is so called because of its being discovered by Torricelli.

Ultra Violet Rays – The sunlight is composed of several colors such as red, orange, yellow, green, blue, indigo and violet. In the spectrum below this color there exist other rays known as ultra violet rays. These rays possess a short wavelength but high frequency.

Ultrasonic – It means frequency in excess of about 20,000 cycles per second.

Virus – Small microscopic agents containing nucleic acid capable of multiplying in an organism and causing many types of diseases such as plague smallpox, mumps, measles, typhus, Poliomytatin etc.

Vitamins – These are minute organic compounds present in food products and are important for maintenance of health. Deficiency of these in food causes deficiency diseases. The most important vitamins are five in number' A, B, C, D and E.

Xerography – It is a new process of graphic reproduction and photography recently developed in India by National Physical laboratory, New Delhi.