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John Dalton revolutionized science in 1803 when he hypothesized that atoms of different chemical elements, such as hydrogen and oxygen, had different characteristic masses. J.J. Thomson discovered the first subatomic particle -the electron - in 1897.
Jun 17, 2011
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Refraction is the bending of light when it goes from one medium to another so, when a ray of light passes through a glass prism, refraction of light occurs both, when it enters the prism as well as when it leaves the prism. Since the refracting surfaces are not parallel, therefore, the emergent ray and incident ray are not parallel to one another. In this case the ray of light is deviated on passing through the prism.
Feb 25, 2016
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Otto Hahn and Fritz Strassman (1902-80) discovered nuclear fission in 1938. When an isotope of uranium-235 was bombarded with neutrons, it split into two lighter nuclei along with, on average, three neutrons. These neutrons were capable of bombarding and splitting other nuclei, causing more fission to take place.
Jun 16, 2011
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Mostly with birthdays and various parties, we see decoration made by colourful balloons which looks amazing and recall the memories of childhood. Have you ever thought why this happens? Why balloon produces pop sound instantaneously rather than leaking air slowly? Let us find out the reason behind it.
Apr 11, 2017
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A spherical mirror is that mirror whose reflecting surface is the part of a hollow sphere of glass. Spherical mirrors are of two types: concave mirrors and convex mirrors. In a concave mirror reflection of light takes place in the bent in surface or concave surface. In a convex mirror the reflection of light takes place at the bulging-out surface or convex surface.
Feb 12, 2016
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Sound is all around us but do you know what is sound. It is a type of energy made up by the vibrations produced. It travels as a wave through a medium like liquid, solid or gas but it does not exist in a vacuum of space. This article deals with the various phenomena of sound with explanation for better understanding.
Oct 27, 2017
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When a red hot piece of iron cools down, it transfers energy to its surroundings in three possible ways: conduction, convection or radiation.
Mar 31, 2011
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A barcode is a square or rectangular image consisting of a series of parallel black lines and white spaces of varying widths. Barcode stores product related data like the date of manufacturing, expiry date, name of the manufacturer, country of the origin and price & quantity of the product. There are two types of barcode one is 1D and other is 2D (2 dimensional).
Apr 2, 2018
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The Solar System consists of the eight planets that orbit our Sun and other celestial bodies such as moons, comets, asteroids, minor planets, and dust and gas. Sun is considered as the centre of the solar system and all the planets revolve around the sun. The eight planets in the solar system in the increasing order of their distance from the Sun are Mercury, Venus, Earth and Mars, Jupiter, Saturn, Uranus and Neptune.
Apr 2, 2018
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The Universe is everything we can touch, feel, sense, measure or detect. It includes living things, planets, stars, galaxies, dust clouds, light, and even time. All the existing matter and space as a whole is considered as universe. The universe is believed to be at least 10 billion light years in diameter and contains a vast number of galaxies each containing millions or billions of stars.
Apr 2, 2018
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The inventor of ball pen was Ladislao José Bíro, a Hungarian born in 1899 into a Jewish family. He invented the ball pen in 1931 to get rid of fountain pen's blotting and smudging.
Mar 8, 2017
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Sound is a form of energy. It is that form of energy which makes us hear. Sound wave is a vibratory disturbance in a medium which carries energy from one point to another without there being a direct contact between the two points. According to Doppler Effect the frequency of sound wave changes with motion, either of the source or of the observer. The reflection of sound wave is called echo. It varies in different mediums.
Mar 8, 2017
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The Doomsday Clock is a symbol which represents the likelihood of a man-made global catastrophe. This clock is taken care of by the members of the Bulletin of the Atomic Scientists since 1947. This clock represents the causes responsible for threat to humanity. If this clock shows 12 O’clock at midnight; it means that the world can end anytime.
Feb 16, 2018
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Some liquids show resistance to motion and it is like internal friction. This is called viscosity. Liquids acquire a free surface when poured in a container. The additional energy that these surfaces have is called surface tension.
Feb 16, 2018
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In the late 1790s, Count Alessandro Volta made the first battery. The first practical primary cell (non-rechargeable) was produced by John Frederic Daniell (1790-1845) in 1836, using zinc and copper electrodes. This was followed by the first secondary (rechargeable) cell invented by Gaston Plante (1834-89) in 1859.
Apr 1, 2011
